Deciding between Fitaly Stamp and Fitaly onscreen

I've been trying the Fitaly Stamp demo for a few days, and I just switched to the Fitaly onscreen demo. I found Fitaly Stamp awkward for about a day, and then liked it. Now I find that Fitaly onscreen feels awkward. I'll try it for a few days, but I'm curious, for those who have used both, which do you like better and why?