My favorite thin keyboard accessory for the iPad has always been the Logitech Ultrathin Keyboard Cover. It's not necessarily because it was the best-looking, or the most feature-packed, but it felt the best to type on, and took up the least amount of space in my bag.
A revised version of the Logitech Ultrathin for iPad Air is now available, with a pretty unexciting and identical name: the Logitech Ultrathin Keyboard Cover for iPad Air. Yeah, it's a mouthful. It costs the same ($100, £75, AU$100), and looks largely the same. But there are some key differences. First, it finally lets you adjust the tilt of an iPad Air while typing. Second, it has a new row of specific iOS-related hotkeys. Third, it has a different latch design.
None of these are enough to ditch the last Ultrathin for the new one, unless you really crave that angle-tilt. What struck me most was that this Ultrathin keyboard really doesn't feel so ultra-thin anymore...or quite so special.
I can't help but notice how much plastic is involved with this Logitech keyboard, especially compared with the mostly metal body of the Belkin QODE Thin Type Keyboard Cover. The Logitech Ultrathin now feels a tiny bit cheap in the way it's built. The magnetic hinge on the side, which used to be metal, is now a slide-up flap of plastic. It pops up when the Air is near and grips onto its side, but it's not as automatic-feeling anymore, or as sturdy. It does eliminate the flippy-flappy metal hinge dangling off the side of the older Ultrathin keyboard, though.