I use dvorak as my daily driver. I'm still able to use qwerty, and while my typing speed is not as fast, it's still adequately usable.

However, an extended typing session in qwerty just feels...weird. I feel vaguely unbalanced, and I'm more likely to get off by one key left or right (while touch-typing). It also tends to put me in four-finger typing mode, rather than eight-finger.

Can any users of Colemak / other layouts who have also used Dvorak comment on whether the Dvorak->Colemak migration is worth it?