When Apple reshuffled the iPod lineup, the iPod touch became something else. It's not the expensive, fancy iPod. Or the cheap, gimped iPhone anymore. It's the iPod.
It's easy to say that it's the best iPod touch ever. (It is.) Every iPod of this generation has evolved in a way in which form tightly hews to function—even the iPhone 4, which is literally constructed around its antenna. So it's worth asking, in this moment when it is the definitive iPod according to Apple, what is its raison d'tre?
The iPod touch is un-possibly thin, so thin you release a slow gasp as you peel it out of the snug, acrylic sarcophagus. The way the polished chrome back bends space around it renders it thinner still, like you're holding a screen imprinted into the space in front of you. (At least, until it's scuffed and scratched and nick into reality, which'll take a few days at most.) You only get a true sense of its dimensions when you plug it in for the first time, extending it into physical space: It's exactly thick enough to accommodate the holes for a dock connector and headphones, which are recessed, cut into the touch's slight, shiny bulge. The physical limits of this design, after two generations, have been breached; the only way to make it thinner is to ditch the 30-pin connector. It fades into nothing in my pocket. I check, over and over, to make sure it's still there.
The price of invisibility is that the lock and volume buttons also dissolve into imperceptibility. The in-line remote and mic has been removed from the headphones as well, in a fit of cheapness by Apple. A sliver of a corner to cut, but it's emblematic of the little ways Apple sabotages the iPod touch's potential.
This iPod touch comes closer than ever to being a true iPhone-without-a-phone—HD video recording! FaceTime! retina display!. Yet, Apple uses lower quality parts all around to keep it from being just that: The "retina display" is a noticeably lower quality panel than the iPhone 4; blacks fade into shimmery grays at even slight viewing angles. It only has 256MB of RAM, half as much as the iPhone 4. It seems to run OS 4.1 just as fast as the iPhone 4, so the most pressing consequence is that you can't keep open as many browser tabs in Safari. That could change in the future, when this iPod touch suddenly might not run the same OS updates as iPhone 4. (It's also strange, given Apple's emphasis on gaming as the touch's primary function, which places the most demand on silicon. Previous touches were at least on par, if not faster than, than their iPhone counterpart.)
The rear camera is disappointing, even if it is a conceit to the physics of thinness. Too wispy to house the 5-megapixel shooter in the iPhone 4, still photos don't even amount to a megapixel. HD video isn't quite as good. It's hard not to long for an iPod touch with the iPhone 4's camera, that could replace the low-end point-and-shoots, Flip cams and dumbphone cameras that line the bottoms of bags and pockets.