... and I do, too. My main reasons are that I can see and use the whole screen and can nevertheless input my text via the (now familiar) Fitaly keyboard without first activating it.
It is also said that the Stamp is more precise as your targets are not below the glass/plastic screen (which means less parallax).
Main advantage for the onscreen Fitaly is in darkness - it is backlighted.
The best (much busier) place for questions and discussions of this kind is the regular Fitaly Forum