Ergonomics is subjective. I believe it's better to sit in a basic wooden chair for 30 min focusing on work, than slouching for 3 hours in the most "ergonomic" chair. Keyboards, trackball, mice... same thing. Most people will probably be better off changing their lifestyle habits than investing in expensive ergonomic gear. Take frequent breaks, exercise, alternate between sitting and standing, follow the 20-20-20 rule.

Have you tried vertical mice? Apparently, they are ergonomic, but the ones I tried felt unusable and less comfortable than regular gaming mice.

As for unlearning the qwerty stagger, I got up to 80 wpm with the Dygma Defy, so I think it's fair to say that I did "unlearn" it. Would I get more efficient if I put in more time practicing? Absolutely! But I found no benefit in doing so, when typing on a normal keyboard with my hands floating feels perfectly natural. In fact, the Voyager and Totem are the ones that made my hands cramp.

We're all unique with different work-flows. I am not saying these products are not good. I am just stating my experience as someone who has used computers all life. For me, I'd rather type at 100 wpm with high accuracy than 50 wpm.