I started having problems with my hands, and switched to a split keyboard. I used them for years, but kept having problems. Now I'm back to a rectangle, with my wrists at an angle to the keyboard, and I don't have problems. I don't think it's the keyboard shape that's the problem, but just how some people align their hands with it. I do credit the years of split keyboards with teaching me proper wrist alignment though. And after getting my fingers used to it, I'm much faster and more accurate on the rectangle. Not to mention I have a real choice when purchasing keyboards again.