Apple iMac 21.5-inch (December 2012) review: The smaller iMac Windows PCs can pick on

For the same $1,299 you could spend on this 21.5-inch Apple iMac, you can buy a 23-inch or even a 27-inch Windows-based all-in-one, and with more robust features.

Yes, for better or for worse, those other PCs have Windows 8. They also have touch screens and optical drives, features that Apple has deemed inessential for a desktop. You might agree with Apple. You might also accept Apple's hallmark design excellence and display quality as worthy substitutions. You might even need or want a particular function of OS X that you can't get in a Windows PC.

Judged purely by its hardware, however, the 21.5-inch iMac is an expensive all-in-one with less functionality than its competition. I would not recommend it to someone looking for the most computer for his or her dollar.

I don't have much to add about the design of the 21.5-inch iMac that I didn't already mention in the review of the more expensive 27-inch model.

As evidenced by the iMac's thin-seeming profile and clean appearance overall, Apple's design lead over the rest of the PC industry remains healthy. You can count me among those who felt disappointed that the new, bulge-backed iMacs were not as thin as Apple originally presented them as being. I quickly got over that disappointment after spending a few minutes with the new design.

Like the 27-inch iMac, the 21.5-inch model has a rounded protrusion on the back of the screen that houses the computing components. You will only notice the bulge when you look at the screen from the most oblique angles. You don't notice its thinness either when you're sitting directly in front of the iMac, but from most other vantage points, the screen appears as thin as its 5-millimeter edge.

That new chassis has only a cosmetic impact on the user. More functionally meaningful in theory is a new glare-resistant screen coating intended to address complaints about too much environmental reflectivity on the previous-generation iMacs.

Our lab -- all long, bright, overhead fluorescents -- is a challenging environment for glare testing. I no longer have the 27-inch iMac on hand to compare, but I know I noticed the reduced glare on the big-screen model when I reviewed it. My impression is that the 21.5-inch iMac is more reflective than the 27-inch version.

I don't have the means to objectively measure reflectivity. My impression could be due to variability in the coating between applications. It could also be a function of the absolute size of the reflected light source hitting the 21.5-inch iMac's comparably smaller viewing area. In any event, while the apparent difference is not enough to ruin the iMac's usability, if you're undecided on screen size and glare is a concern, you might head down to your local Apple Store and compare the screens yourself.

	Apple iMac	Vizio CA24T-A4	Asus ET2300INTI
Price	$1,299	$1,249	$1,299
Display size/resolution	21.5-inch, 1,920x1,080	24-inch, 1,920x1,080 touch screen	23-inch, 1,920x1,080 touch screen
CPU	2.7GHz Intel Core i5-3330S	2.5GHz Intel Core i5-3210M	3GHz Intel Core i5-3330
Memory	8GB 1,333MHZ DDR3 SDRAM	6GB 1,333MHZ DDR3 SDRAM	8GB 1,333MHZ DDR3 SDRAM
Graphics	512MB Nvidia GeForce GT640M	32MB Intel HD Graphics 4000	1GB Nvidia GeForce GT630M
Hard drives	1TB, 5,400rpm	1TB, 5,400rpm	1TB, 7,200rpm
Optical drive	None	None	Dual-layer DVD burner
Networking	Gigabit Ethernet, 802.11b/g/n wireless	Gigabit Ethernet, 802.11b/g/n wireless	Gigabit Ethernet, 802.11b/g/n wireless
Operating system	OS X 10.8 (Mountain Lion)	Windows 8 (64-bit)	Windows 8 (64-bit)

I include the Vizio CA24T-A4 in the above comparison to highlight multiple Windows PCs that have larger screens than this iMac, but the Asus ET2300INTI is the more challenging comparison for Apple. The Asus system also has a larger screen, as well as a faster CPU than the iMac.

Like many Windows all-in-ones, the Asus ET2300INTI has an HDMI input, as well as an HDMI output. Before you call out the iMac's Thunderbolt ports, know that the Asus has two of them. On the iMac, you'll need to use one of the Thunderbolt ports and connect an adapter in order to use it with an HDMI-based device, adding expense and complication.

The combination of HDMI and Thunderbolt gives the Asus a significant edge over the iMac in terms of its out-of-the-box connectivity options. Yes, the Asus also has built-in WiDi capability, an eSATA port, and the aforementioned touch screen and DVD burner, but it's the combination of ports that really extends its usability. With HDMI alongside Thunderbolt, you can connect a cable box, a game console, an HD camcorder, or some other assortment of video source devices to the Asus system, adapter-free, and still have room to add a fast Thunderbolt data array. With the iMac you'll need a bird's nest of expensive adapters or Thunderbolt cables or both for the same functionality.

How many people will actually use those inputs on either system, much less in combination? Great question, and I don't know the answer. But I do know that, all else equal, I'd rather my $1,299 afforded me the most convenient option.