Since then, ultrabooks have become both more common and less expensive. Asus now makes several UX variations, including three that we are reviewing, the UX31A, UX32A, and UX32VD. At $779, the Zenbook UX32A is the least expensive of the current crop, but for good reason.

The UX32A still has a previous-generation Intel Core i5 CPU. That generation of chip is known by the code name Sandy Bridge, as opposed to the latest generation, released in the second half of 2012, and known as Ivy Bridge. The UX32A is also missing other Intel improvements, most notably the HD 4000 integrated graphics, which offer improved gaming performance in other notebooks.

By way of comparison, the 13-inch Asus Zenbook UX32VD comes alluringly close to being an ultrabook without compromise. For $1,299 it includes an Intel Core i7 CPU, a full HD 1,920x1,080-pixel-resolution display, and a discrete Nvida 620M GPU. That model is the closest hybrid of a 13-inch ultrabook and a full-power mainstream laptop to date, and easily my favorite of this collection of Zenbooks, despite its higher price.

The UX31A is a more upscale design variant, thinner with a more unibody chassis, which skips the GPU, but keeps the high-res screen and Ivy Bridge internal hardware. But at about $1,079, it doesn't make the most compelling value case.

If you just love the Zenbook look and feel, then this third version, the UX32A, is a way to get it for under $800, albeit with outdated components and some performance compromises. If your ultrabook needs are that basic, there are many other worthwhile options out there to consider at around the same price.

Asus Zenbook models compared

	CPU	GPU	Storage	Display	Price
UX32VD	1.7GHz Core i7-3517U	Nvidia GeForce 620M	500GB HDD/24GB SSD	1,920x1,080	$1,299
UX32A	1.4GHz Intel i3-2367M	Intel HD 3000	320GB HDD/32GB SSD	1,333x768	$779
UX31A	1.7GHz Intel Core i5-3317U	Intel HD 4000	128GB SSD	1,920x1,080	$1,079

Asus Zenbook UX32A specs

Price as reviewed	$779
Processor	1.4GHz Intel Core i3-2367M
Memory	4GB, 1,333MHz DDR3
Hard drive	500GB 5,400rpm / 32GB SSD
Chipset	Intel HM76
Graphics	Intel HD 3000
Operating system	Windows 7 Home Premium (64-bit)
Dimensions (WD)	12.8x8.8 inches
Height	0.2 - 0.7 inch
Screen size (diagonal)	13.3 inches
System weight / Weight with AC adapter	3.3 pounds / 3.8 pounds
Category	13-inch

The look and feel of the Zenbook line has changed little since last year. The tapered aluminum design of the original Zenbook was both minimalist and the most Air-like of the early ultrabooks (at least until the Dell XPS 13 came around). But it also had a few design miscues. The lid on the original Zenbook was notoriously hard to open. That's been fixed in the UX32A, and the touch pad also feels more responsive than the older models', especially after a last-minute software update from Asus, although it's still one of the system's weak points.

The original Zenbook was thinner and lighter than this version, but both the more tapered Zenbooks (such as the current UX31A) and this one have a sharp front lip that can be murder on the heels of your hands, depending on your typing style. Ergonomics aside, the solid-feeling aluminum body is not as streamlined in its construction as a MacBook, but the parts fit together well, with minimal screws and seams.

The keyboard was a weak point on the original Zenbook, with shallow, clacky keys. The UX32A and UX32VD both have a slightly thicker and heavier body, and that extra depth lets the keyboard have a little more space. Keystrokes on the UX32A feel more like they do on a standard laptop than on the thinner, more tapered UX31A (which is more like the original 2011 Zenbook). The keyboard is also backlit, a must-have feature on any modern ultrabook.

The large but finicky clickpad on that original UX31 was one of our main problems. If you make sure to install the latest touch-pad drivers (version 1.0.26), which are available via Asus Live Update if not preinstalled on the system, the touch-pad experience is much improved, but it's still nowhere near as intuitive or responsive as a MacBook trackpad -- a Windows-wide problem. There is, however, a decent set of multitouch gestures, demoed and controlled by the Asus Smart Gesture software app. One nice feature is that you can set a two-finger tap to indicate a right-click, a very Mac-like move that I've seen popping up in a few Windows laptops lately.

In the UX32VD and UX31A models, the display has been upgraded to an IPS screen in full HD, with a 1,920x1,080-pixel native resolution. In this less-expensive model, you're still stuck with a 1,366x768 native resolution. Most 13-inch laptops, including some very expensive ones, have 1,366x768-pixel screens. That's fine for $800 or so, so it's not out of place in this configuration. That said, an upscale ultrabook could really benefit from at least a 1,600x900-pixel display, which feels to me like the sweet spot for a 13-inch laptop. The screen itself looked decent, and was thankfully not excessively glossy, which often causes annoying glare from nearby lights.

Audio through a speaker grille at the very top of the keyboard tray was predictably thin, despite the Bang & Olufsen ICE Power branding (which you'll find on all three Zenbooks). Audio volume controls are mapped to alternate F-key functions, so you'll need to hit, for example, Fn+F10 to mute the sound.

	Asus Zenbook UX32A	Average for category [13-inch]
Video	HDMI, Mini-DisplayPort (plus VGA via dongle)	HDMI or DisplayPort
Audio	Stereo speakers, headphone jack	Stereo speakers, headphone/microphone jacks
Data	3 USB 3.0, SD card slot	2 USB 3.0, 1 USB 2.0, SD card reader
Networking	Ethernet via dongle, 802.11n Wi-Fi, Bluetooth	Ethernet, 802.11n Wi-Fi, Bluetooth, optional mobile broadband
Optical drive	None	DVD burner

With dual video outputs and three USB 3.0 jacks, the UX32A makes good use of its slightly thicker body to fit in more ports. Going all-3.0 is especially impressive considering the $779 price (thank the Intel HM76 chipset). Ethernet is still relegated to an external dongle, but this system does include Intel's Wireless Display feature, which enables you to send the screen image to a TV or other monitor via a $99 sold-separately receiver box.

The other two Zenbook laptops we're reviewing for summer 2012 have made the jump to Intel's third-generation Core i-series processors, but not this one. That puts the UX32A at a considerable disadvantage. The $1,299 UX32VD has a 1.7GHz Intel Core i7-3517U along with a 500GB hard drive/24GB solid-state drive (SSD) combo drive, and Nvidia GeForce 620M graphics. The $779 UX32A has a previous-generation 1.4GHz Intel i3-2367M CPU, 320GB HDD/24GB SSD, and Intel HD 3000 graphics, and the $1,079 UX31A has a 1.7GHz Intel Core i5-3317U CPU, 128GB SSD, and Intel HD 4000 graphics, plus a slightly thinner body.

Of those three, the UX32VD is the most expensive, but also by far the most universally useful. It was also much faster at running our benchmark tests, beating out the other two Zenbooks, but falling behind an Intel Core i5 MacBook Air. In everyday use, I found all three to be more than responsive enough for common computer tasks, from social networking to working in Microsoft Office to running Photoshop. But there's definitely a difference between Sandy Bridge and Ivy Bridge performance.

If you're at all interested in gaming, the UX32VD is the Zenbook for you. Even then, the Nvidia GeForce 620M GPU is an entry-level part, and not great for high-detail settings at full 1,920x1,080-pixel resolution. The Intel HD 3000 integrated graphics in the UX32A ran our very forgiving Street Fighter IV test at 1,366x768 pixels and only 19.9 frames per second, making it not very well suited for anything beyond simple casual games and maybe a few vintage games.

All three of the Asus Zenbook models we tested had solid battery life, to varying degrees. The UX32A ran for 5 hours and 16 minutes -- decent if not spectacular -- in our video-playback battery drain test, while the UX31A ran for 6 hours and 16 minutes. The UX32VD has higher-end components, so it may be forgiven for only running for 5 hours and 13 minutes. Some other ultrabooks can run for 1 to 2 hours longer, but all these times should get you through a full day if you close the lid and put the laptop to sleep when not actively using it.

Asus offers a one-year mail-in warranty on each of these ultrabooks. The Asus Web site can get a little confusing to navigate, but 24-7 phone support is available at 888-678-3688. The simplest way to find the Asus support section for your specific model is to ignore the frustrating pop-up navigation menus and simply type the model number into the support page search box.

The Asus Zenbook UX32A shares a chassis with the UX32VD model we also reviewed, but little else. It's stuck with an older CPU, lacks the graphics and battery-life advantages of Intel's new Ivy Bridge platform, and has a lower-resolution screen. That said, if you love the look and feel, which is nicely MacBook-like, this model is about $500 less.

Find out more about how we test laptops.

System configurations:

Asus Zenbook Prime UX32A
Windows 7 Home Premium (64-bit) w/ SP1; 1.4GHz Intel Core i3-2367M; 4GB DDR3 SDRAM 1,333MHz; 64MB (Dedicated) Intel HD 4000; 320GB Hitachi 5,400rpm

Acer Aspire S5-391-9880
Windows 7 Home Premium (64-bit) w/ SP1; 1.7GHz Intel Core i5-3317U; 4GB DDR3 SDRAM 1,333MHz; 128MB (Dedicated) Intel HD 4000; 256GB Lite-On IT SSD (2x RAID 0)

Asus Zenbook Prime UX32VD
Windows 7 Home Premium (64-bit) w/ SP1; 1.9GHz Intel Core i7-3517U; 4GB DDR3 SDRAM 1,333MHz; 1GB Nvidia GeForce GT 620M / 64MB (Dedicated) Intel HD 4000; 500GB Hitachi 5,400rpm

Apple MacBook Air 13.3-inch (Summer 2012)
OS X 10.7.4 Lion; 1.8GHz Intel Core i5; 4GB DDR3 SDRAM 1,600MHz; 384MB (Shared) Intel HD 4000; 128GB Apple SSD

Asus Zenbook Prime UX31A
Windows 7 Home Premium (64-bit) w/ SP1; 1.7GHz Intel Core i5-3317U; 4GB DDR3 SDRAM 1,600MHz; 64MB (Dedicated) Intel HD 4000; 128GB Adata XM11 SSD