ste-phan,

If you get a n900, you would need to set-up extras devel&testing, install CSSU then install CSSU thumb...

The N9 is pretty simple; start using it straight away...

Are you speaking about the back arrow in a Message Conversation? It's present only in some instances anyway...I think maybe you used it in pr1.0 or pr1.1 as I do remember reading somewhere it was fixed in pr1.2...If you tell me which one i can check it now

The capacitative screen of the n9 adds to the better usability of the n9 compared to the resistive on of the n900...I speak this as owner of both phones so if you come from another capacitative screen phone like the OP, the n9 is much much easier to get used to than the n900...