I'm tempted to try out minimak. My only concern is that... do the numbers that get thrown around about percentage improvement only apply to touch typists?
I've never been strict enough with myself to learn touch typing (I still hit 120WPM so speed isn't an issue) and worry that the benefit won't be as obvious.
The metric I lean on the most is the one published by Andong at http://www.andong.co.uk/dvorak/Default.aspx. I guess that's odd since I spent the least amount of time talking about it and put it at the bottom of the page. It is focused on metrics of efficiency and effort. If you wanted speed, you might want to look at things like finger distance and home row usage more closely, in which case Arensito or Colemak might have an edge.
I've never been strict enough with myself to learn touch typing (I still hit 120WPM so speed isn't an issue) and worry that the benefit won't be as obvious.