I did some other tests.
So, main problems come when i switch to full res mode and work 100% on screen with sharpening and NR sliders. Anyway when i am in full res mode also other controls are slow sometimes, like WB and colour settings. This doesn't happen when i am in "normal" mode. Just a questione: when i am in full res mode can't i go back to normal mode? i try to click on the full res icon again but nothing happens, is this normal ?
I managed to work in a decent manner by working in normal mode and only at the end of the workflow switch to full res mode for 100% on screen adjustments. But, of course, i would like to work always with full res mode, if possible!
Anyway Dp2 merrill files are amazing, if i can manage to resolve these software problems i will buy one for sure..now i go on searching on the web for more x3f files to try and have fun with.
Forgot to say that i set up my preferences to work in Prophoto mode, but i am quite sure this isn't why i am having those problems i told about before.
Thank you guys and sorry for being a bit boring with this stuff