For those of you who missed the original post:
Kinesis Advantage Pro USB
Work ended up ordering it from Fentek rather than buying a refurb unit directly from Kinesis; I got a new keyboard for about a $15-20 savings over the refurb.
Turns out that Fentek carries a whole bunch of alternative keyboards, including the DataHand (tres cool, but has a much steeper adaptation curve and is amazingly expensive) and the Comfort Keyboard System (pretty, adjustable, but still basically a flat keyboard... bleh).
But back to the Kinesis...
The key feel is excellent. It's actually somewhat close to what I remember on the old IBM Selectric typewriters; a touch springy, full-travel with a smooth stroke. The touch is a lot softer, though, than any full-travel keyboard I've used, and I'm noticing that when I use the Microsoft "ergo" keyboard that's still plugged into the laptop.
The basic hand position is also really nice now that I've got used to it. I think that was actually the most difficult bit. It's a much more relaxed wrist position, much straighter than a standard keyboard that brings your hands together in front of you. Most of the bad reaches I was trying to make (and missing) seem to have been caused by my hands being twisted on the keyboard.
I've got to order one of these for home.