For me it’s the wireless module that is game changer.I've been using Zowie mice for going on 10 years now. I don't know if they retained their quality after being bought out by BenQ. I currently have the EC1-B I think, the large version.
Debated upgrading from time to time but its a great mouse and at this point in the game I don't know if upgraded sensors matter or not.
But to be honest I am not picky, still have orochi, but it’s visibly less smooth than Zowie (but zowie was 150$)
I like the matte black surface, very comfortable mice
Movement of the cursor is smoooooth and uninterrupted
Very pleasant to play RPGs, RTS, shooters