For some very odd reason, I find myself typing as much as 20-30 wpm faster (so something like 150wpm-ish with 98+% accuracy, or so the typing tests say) on the low profile Apple keyboards (I have the bluetooth one, and my MacBook's keyboard) than on any other keyboard I've used. It makes a noticeable dent in the time it takes to reply to emails and to get my point across in IM and IRC.

Maybe it's the lesser effort required to press the key. The same effect happens when I'm playing the piano on certain pianos like that..just so much easier to play faster.

I second that. Another great feature is how close and tight the plastic keys are to the metal base: very few things can slip underneath them, and the keyboard stays exceptionally clean.

I bought the bluetooth version last week and I am very happy with it so far. It's almost the same as my MBP's keyboard, so the transition is not bad. The itunes controls are handy too.

I agree. The feedback is the best I've felt. However, I also like the spacing and arrangement of the keys.