@xatax : I was using an ASUS MYPAL A620 which was on of the most powerfull of it's generation according to the tests i've read about it before buying... I switched to the Z for the swiveling screen, the 640x480 resolution, the choice of programs (you can run virtually any opensource program you want to), the multithreaded environment (x11) ,being able to learn c++ during my transport times etc ...
I didn't meant winCE devices are superior in any way ... just being surprised by the lack of optimisations in a few usages where PDAs can be quite good...
@sigmaX : right, some kind of "wineCE" could be fun hope we'll see it one day