Dvorak works really well for me. (Though you might want to pick Colemak or Neo2 these days.) I use Dvorak on both my Kinesis Advantage and on 'normal' keyboards like on a laptop.
My personal experience after switching to Colemak is mostly neutral. Speed is about the same after some training, around 70 WPM. Comfort, maybe improved a bit, but no life changing.
Some people claim that they went from 60 WPM on Qwerty to over 100 WPM on some other newly designed layout, but my experience is clear: if you do it for the speed you will be disappointed.
My personal experience after switching to Colemak is mostly neutral. Speed is about the same after some training, around 70 WPM. Comfort, maybe improved a bit, but no life changing.
Some people claim that they went from 60 WPM on Qwerty to over 100 WPM on some other newly designed layout, but my experience is clear: if you do it for the speed you will be disappointed.