It's not a new keyboard, and I've used similar ones on many other recent ThinkPads, but after using and reviewing so many other laptops, it was a welcome change of pace to put my fingers on the keys and feel an immediate difference. However, there's a flip side. (Not literally.) A couple of jarring changes in the standard keyboard layout might drive you crazy, as described below.

There are a lot of premium (read: expensive) features packed into the new X1. The 14-inch display is a touch screen with a very high 2,560x1,440-pixel resolution (a less expensive 1,600x900 screen is also available, but for $1,299 and up it seems like a bad deal). Prices and configurations on the Lenovo Web site have changed more than once just while I was writing this review, with starting prices jumping from $1,299 to $1,499, and dropping back down to $1,299. As of right now, the 1,600x900-pixel-display version starts at $1,299, while the 2,560x1,440 version starts at $1,399. Our specific system starts with the higher-res touch screen, combining it with a Core i5 CPU, 128GB solid-state drive (SSD), and 8GB RAM for $1,679 -- according to Lenovo, although this exact configuration does not seem to be available on the Lenovo Web site right now.

There's one extra new feature that makes the X1 Carbon stand out even more from the crowd -- something Lenovo calls an adaptive keyboard. This replaces the function key row at the very top of the keyboard with a small touch-screen strip that changes based on the app you're using. There are four presets with different commands, including ones for Web browsing and VOIP use.

It's a pretty clever concept, and the strip changed automatically when we opened different applications, which was an unexpected bonus. But it's also more of a party trick than a game-changer, and it won't convince you to drop $1,300 to $2,000 on the X1 Carbon if you were planning to spend significantly less on something else.

Instead, if you're considering the X1 Carbon, you're probably looking for a very lightweight laptop, with a larger, higher-res screen than most slim ultrabooks; premium design and construction, including the best keyboard and touch pad in the Windows world; and the IT chops, including vPro and TPM, to play nice with corporate networks.

	Lenovo ThinkPad X1 Carbon	Samsung Ativ Book 9 Plus	Apple MacBook Pro 13-inch (October 2013)
Price	$1,679	$1,399	$1,499
Display size/resolution	14.0-inch, 2,560x1,440 touch screen	13.3-inch, 3,200x1,800 touch screen	13.3-inch, 2,560x1,600 screen
PC CPU	1.6GHz Intel Core i5-4200U	1.6GHz Intel Core i5-4200U	2.4GHz Intel Core i7-4850HQ
PC memory	8GB DDR3 SDRAM 1,600MHz	8GB DDR3 SDRAM 1,600MHz	8GB DDR3 SDRAM 1,600MHz
Graphics	1,792MB (shared) Intel HD Graphics 4400	1,749MB (shared) Intel HD Graphics 4400	1GB Intel Iris Graphics
Storage	128GB SSD	128GB SSD	256GB SSD
Optical drive	None	None	None
Networking	802.11ac wireless, Bluetooth 4.0	802.11b/g/n wireless, Bluetooth 4.0	802.11ac wireless, Bluetooth 4.0
Operating system	Windows 8.1 (64-bit)	Windows 8 (64-bit)	OS X Mavericks 10.9

Design and features
Lenovo says this is the lightest 14-inch laptop in the world, and at 3.1 pounds, it certainly weighs less than many 13-inch laptops (and if you skip the touch screen, it can get down to 2.9 pounds). The carbon fiber body helps keep it light, and also adds strength and durability. Like previous versions of the X1, the notebook's display folds back 180 degrees, allowing you to lay the system down flat, or at least find the perfect angle when you're in a cramped meeting room or coffee shop.

In overall look and feel it's nearly identical to last year's X1 Carbon, although that system weighed a hair more. Both are cast in matte black, tapering toward the front lip, and with a squared-off rear edge. This year's Carbon is not as flashy as even some of Lenovo's other laptops, such as the excellent Yoga 2 Pro, but there's a timelessness to the design that should hold up in the office or on the road.

One of the big selling points is Lenovo's meticulously crafted keyboard. This version retains the modified island-style keys used in the previous X1 and most of the current ThinkPad line. It's also backlit, which is a feature every travel-oriented laptop should have. As with other island-style Lenovo keyboards, the individual keys have a slightly convex curve at the bottom, which helps with missed keystrokes. Even on this slim chassis, the keys have excellent depth and solid, tactile feedback.

Despite my praise for this keyboard, there is one part of the layout that drives me completely crazy. The Backspace key now sits just to the left of a smaller Delete key. The latter is more typically found on the function key row (or on MacBooks, not found at all). Because Backspace was no longer the key at the top right corner of the keyboard, I inevitably hit Delete when I meant to hit Backspace. It sounds like a small thing, but it was a serious impediment to productivity when working on the X1, and I'm frankly surprised this layout issue passed the usually laser-focused minds at Lenovo. The Caps Lock key has also been replaced by a split Home/End key. That change bothered me less, but touch typists will no doubt stumble over this as well.

The touch pad also gets an upgrade from last year's X1. It now follows the model of other recent ThinkPads, ditching the last vestiges of physical mouse buttons -- both the under-the-pad buttons and the second set above the pad, for use with the red trackpoint nestled between the G, H, and B buttons. Both sets of mouse buttons are built into the pad itself, clickpad-style.

I found the touch pad's sensitivity to be cranked way up by default, and the settings required some tweaking to feel comfortable. Finding the touch-pad settings was a bit of an adventure, as there are competing settings sections from Microsoft and Lenovo. It's not obvious, but use Windows 8 search and search for "mouse," not "mouse and touch-pad settings," and from there, you'll see a ThinkPad tab that takes you to the custom settings. I also had to reduce the size of the touch pad's swipe-in zone, as I was always accidentally activating the Charms bar in Windows 8 during casual navigation.

The adaptive keyboard is a clever idea I have yet to see on another laptop, although it could certainly trickle down into other Lenovo systems if well-received here. The adaptive strip, which replaces the function key row, looks a bit like an e-ink display, but it's actually a liquid crystal layer, cleverly backlit to work in any lighting conditions.

Different apps cause the row to switch between four presets. For example, launching Chrome, Safari, or IE will give you a row of commands including a page-reload button and a new tab button; launching Skype or Google Talk gives you microphone controls. The Windows 8 menu screen has buttons for accessing cloud storage, voice and gesture recognition software, and the full Windows 8 app list.

It's an interesting idea, and works as advertised. That said, I don't see it as being enough to sway your purchase decision one way or another. The commands are not programmable, and three of the four rows of commands actually share most of the same buttons. That said, I'd love to see this idea expanded into other systems, and with the ability to create custom commands.

The 14-inch touch screen is a system highlight, thanks to its 2,560x1,440-pixel native resolution. There is a lower-res screen option available, a mere 1,600x900 pixels, but that seems like a poor way to save a few bucks on an already expensive laptop. The display has a matte finish that still allows colors to pop, while keeping glare down, and the screen looks good even from wide viewing angles.

Ports and connections	Lenovo ThinkPad X1 Carbon
Video	HDMI, Mini DisplayPort
Audio	Stereo speakers, combo headphone/microphone jack
Data	2 USB 3.0
Networking	Ethernet (via dongle), 802.11ac Wi-Fi, Bluetooth
Optical drive	None

Connections, performance, and battery
Like many business systems, the X1 Carbon skips the SD card slot (a security concern for some), but you do get two video outputs, both HDMI and Mini DisplayPort. Ethernet requires a dongle, but Lenovo would no doubt like you to use one of its OneLink docks to add additional connectivity, including DVI, full Ethernet, and four USB 3.0 ports. That standalone dock costs $179, a hefty additional investment, but I use an older USB-powered version, and have found it to be excellent.

In our benchmark tests, the Core i5-powered X1 Carbon performed as expected when compared with other recent ultrabooks with higher-than-1080p displays. Nearly all these systems have fourth-gen Core i5 CPUs, from Intel's ultra-low-power line (except the Toshiba Kirabook, which has a previous-generation Core i7), and you'll find any of these more than powerful enough for everyday personal and business tasks, from putting together PowerPoint presentations to social media and Web surfing to streaming HD video.

Given all that, what we're really looking for from the X1 Carbon is amazing battery life. A slim, on-the-go laptop needs to last all day, and while the X1 does well, it's not a long-lived as some. The system ran for 5 hours, 41 minutes, in our video playback battery drain test, which is merely OK, and not in the same ballpark as the 13-inch MacBook Pro, nor even the Samsung Ativ Book 9 Plus or Lenovo Yoga 2 Pro. Keep in mind that all of the systems mentioned here have better-than-HD displays.

Conclusion
The third version of the ThinkPad X1 is the best to date, and it remains one of the only choices for a slim, high-design business laptop with premium features. The addition of both a 2,560x1,440-pixel-resolution display and the adaptive function key row is welcome, but these upgrades also drive the price up high enough that you're likely to have to twist some arms to get your IT department to get this as your next work laptop.

HandBrake multimedia multitasking test (in seconds)

(Shorter bars indicate better performance)

Lenovo IdeaPad Yoga 2 Pro
391

Apple MacBook Pro 13-inch (October 2013)

445

Lenovo ThinkPad X1 Carbon (2014)

482

Samsung Ativ Book 9 Plus

506

Adobe Photoshop CS5 image-processing test (in seconds)

(Shorter bars indicate better performance)

Toshiba Kirabook
230

Apple MacBook Pro 13-inch (October 2013)

244

Samsung Ativ Book 9 Plus

248

Lenovo ThinkPad X1 Carbon (2014)

266

Lenovo IdeaPad Yoga 2 Pro

302

Apple iTunes encoding test (in seconds)

(Shorter bars indicate better performance)

Apple MacBook Pro 13-inch (October 2013)
73

Toshiba Kirabook

104

Samsung Ativ Book 9 Plus

119

Lenovo ThinkPad X1 Carbon (2014)

120

Lenovo IdeaPad Yoga 2 Pro

121

Video playback battery drain test (in minutes)

(Longer bars indicate better performance)

Apple MacBook Pro 13-inch (October 2013)
782

Samsung Ativ Book 9 Plus

509

Lenovo IdeaPad Yoga 2 Pro

430

Lenovo ThinkPad X1 Carbon (2014)

341

Toshiba Kirabook

305

Find more shopping tips in our Laptop Buying Guide.

Lenovo ThinkPad X1 Carbon (2014)
Windows 8.1 (64-bit); 1.6GHz Intel Core i5-4200U; 8GB DDR3 SDRAM 1,600MHz; 1,792MB (shared) Intel HD Graphics 4400; 128GB Samsung SSD

Apple MacBook Pro 13-inch (October 2013)
OSX 10.9 Mavericks; 2.4GHz Intel Core i5-4258U; 8GB DDR3 SDRAM 1,600MHz; 1GB Intel Iris Graphics; 256GB Apple SSD

Samsung Ativ Book 9 Plus
Windows 8 (64-bit); 1.6GHz Intel Core i5-4200U; 4GB DDR3 SDRAM 1,600MHz; 1,749MB (shared) Intel HD Graphics 4400: 128GB SSD

Lenovo IdeaPad Yoga 2 Pro
Windows 8.1 (64.bit); 1.6GHZ Intel Core i5-4200U; 4GB DDR3 SDRAM 1,600MHz; 1,792MB (shared) Intel HD 4400 Graphics; 128GB Samsung SSD

Toshiba Kirabook
Windows 8 (64-bit); 2GHz Intel Core i7-3667U; 8GB DDR3 SDRAM 1,600MHz; 32MB (Dedicated) Intel HD 4000; 256GB Toshiba SSD