Yeah I alternate between my Apple wireless keyboards and a cooler master mechanical board with cherry browns. I definitely enjoy them both but I find that it's the position of my arms that has the largest effect on wrist fatigue, not the key actions. Ideally I'd like to mount mechanical keyboards on the arm rests instead of Apple keyboards, but I haven't found a wireless one that I like yet...
I've tried several different varieties of "mechanical" keyboards, including buckling-spring keyboards, and I've come to the conclusion that I genuinely prefer laptop-style keyboards that have a hard stop for my fingers. (Specifically, I type on ThinkPad keyboards, even on desktops and docked systems; I use USB ThinkPad keyboards, complete with the mouse on home row.)
I don't type "through" the hard stop; my fingers know to stop right at the hard stop, but I prefer a physical stop rather than just a change (subtle or otherwise) in the amount of pressure I have to apply. I also like the very small amount of travel in the key.
I'd sort of agre with this, I find I type fastest these days on my bluetooth apple keyboard but my personal favourite is still my TiBook semi-trsnaparent keyboard, it had a comfortable amount of travel and great action.