A great hook for me but the fluctuating quality of these keyboards. My first NEK 4000 was in service for 4 years without any problem. No keys abrasion, no weakening at the keys, no rattling. Unfortunately landed an ugly day the inevitable coffee in the keyboard and the palm rest was nevertheless become somewhat unsightly after all this time, so that then but a new was needed. Big Mistake. In the past 3 years I have been through 4 of those things. The biggest weakness (why again even now a new keyboard is due) seems to be the bottom row of keys (Ctrl, Alt, Spacebar etc), because these keys are quite unreliable in my usage after some time. Furthermore, was seen in all 4 of my previous "bad" NEKS after a few weeks of the first keys abrasion. Useful if you do not really need to print on each key.
Conclusion for me: Ergonomic in "humane" price range (below 100) is currently the best keyboard. Unfortunately, the low price seems to be going well at the expense of quality. If MS a "Premium" - or "Pro" version at a higher price on the market bring with corresponding thereto quality, that would be my dream. Unfortunately, there are no such keyboard, so you probably have to bite the bullet of moderate quality when the wrists require it.