I personally use a regular keyboard rather than a split ergonomic keyboard; I've never really had any discomfort even typing for long periods, so have never really felt the need, and I have a tenkeyless keyboard that I'm very happy with.

The main thing that I notice when I try out split keyboards is that the middle keys on the keyboard are forced to "choose a side". My typing style admits some degree of alternation; I may use my left hand to hit the 'h', especially when my right hand is doing punctuation work on the side of the keyboard.

So my question is why aren't these keys simply replicated. Just have t/y,g/h,v/b/n on both sides of the divide so that you don't have to make a choice; just like the spacebar is replicated.