It is true that I miss some precission by using my mouse with a PS/2 port instead of the USB one, because the Logitech software tell me that it "may" miss some precission. What do you think?
IMO, I think that you should uninstall the mouse software. Installing it isn't required for the mouse to run properly. It adds some extra crap that you don't need. I have a Logitech mouse also and I should know.
Nah, it works rather good on ps/2 imo. I switched to usb since it bitching with me and always popping out. It's harder to put it into the ps/2 port than the usb. It works well on ps/2 anyway, do as you wish.