I personally went QWERTY -> Dvorak -> Workman. While I spent under 2 years with Dvorak, I have been using Workman for over 3 years now and think I'll likely stick with it. There are other crazy layouts like QGMLWB and Halmak, but I think their higher on-paper efficiency comes at the cost of other things, and Workman seemed like it struck the best balance to me. I had comfort/ergonomics in mind and was trying to get away from some hand pain which seemed to only switch hands going from QWERTY to Dvorak, but is now gone with Workman.