Tried one awhile ago and kept it because it's so nice. I even put up with the hassle of relearning the keys, which was frustrating at times. I am a touch typist, but I had to start staring at the keys a bit more to compensate for the different feel of my Natural Elite. Now, I switch from standard to natural without any trouble.
MS keyboards are just made exceptionally well -- better than any other I've had (including Logitech). I would, however, like to execute the pea-brained moron who screwed up the arrow keys on the Elite.
The only other problem is that on FPS games, I have a tendency to hit the "Windows" key with my left hand since it's right near Z, X, and C which I always have programmed to something -- the button is huge, too. In Half-Life games, it changes to the desktop and kills the sound when you switch back, requiring a reboot.

So, I took a screwdriver and popped the button off. Problem solved.
