Good points Shai, and thanks for the response.
The one thing that those keyboards in the linked articles have in common is that the control keys are much closer to the space bar than they are on most modern keyboards.
Your points about error rates and benefits for other applications are something I hadn't thought about and since I'm not RMS, I don't spend all my time in emacs.
Perhaps the solution is a pair of foot-pedals: one for control and one for alt/meta. I'm only half-joking here.
I'll take your advice and see how it pans out.
I've discovered that Shai is a vim user, so I hope that emacs users are welcome here *g*.
I see that Colemak keeps the x and c keys in the same place, which looks good. One problem I had when I looked at Dvorak was all the emacs keys getting garbled.
Has anyone tried making caps-lock a control key (as seems to be common amongst emacs users anyway) and making the left control key a backspace?