I just tried one of these in the store. Let me tell you: I'm happy with it. I've got a few Cherry keyboards (Red, Brown, and Blue) but I always find myself most comfortable on the MS Ergonomic 4000 due to the layout of the keys. Note that I cut the rubber domes to make them softer, as I find them too stiff from the factory.
This "pelvis" keyboard gets everything that the MS 4000 did right, and fixes some of the things that they've done wrong. For one thing, the keys are relatively soft, I would say on par with a Cherry Brown ~55-60 grams. However the travel is much shorter: these bottom out at about 2 mm, just about where the Cherry registers a keypress. Therefore, one needs a light hand to type comfortably on this board.
The hand layout is about perfect, and with the bulky numpad gone it sits better in the middle of your body. On the MS 4000 the arrow keys were too far away from the home row, but on the pelvis keyboard they are quite a bit closer. All the buttons that didn't work on Linux anyway are gone, such as the scroll and media keys. I don't like the insert-delete-home-end block, though. I do like the switch for Function keys or Media keys, as the MS 4000 drives me nuts when it is in Media mode and the function keys don't work.
Oh, and the thing is beautiful in person.
