This review (Japanese) contains four opinions on the new Happy Hacking Keyboard Pro 2, which is a USB 2.0 model. In general, people seem to like the feel, but there was consistent concern over the fact that larger keys such as control and shift did not go down as smoothly when not pressed exactly in the center.
That’s a bit worrisome for a $250 keyboard.
Also, found a FAQ about the Avant Prime’s programmability. Apparently, the remap function works by specifying a source key and a destination key for the remapping.. which means it may be impossible to program keys needed for the Mac’s volume and eject functions.
I wish Apple would just produce a high-end keyboard. They produce all kinds of high end stuff anyways, is it that much more to ask? Mighty Keyboard perhaps?