Okay let me clear all this up!!!
The differences between MOST quartz and 7750 Audemars Puget ROO is as follows:
Quartz compared to 7750:
The quartz has the sub-dials much closer to the center of the dial than the 7750.
The quartz ticks, and resets very slowly (The second hand go's around clockwise once when reset.)
The sub-dial layout on the quartz is different than the 7750. (See below)
The cases are built differently (In my experiance) the quartz is much harder to disassemble. (Different screw system, not cosmetic.)
THE SUB-DIAL LAYOUT!
The sub-dials on the 7750 are PROPER, second at 12 O' Clock, Minute at 9 O' Clock, and hour at 6 O'Clock.
The sub-dials on the quartz are as follows, second at 6 O' Clock, minute at 12 O' Clock, and hour at 9 O' Clock.
Now the big but, and it is a big one. There are quartz movements currently available in the Rubens Barrichello II reps that have the PROPER sub-dial layout, and the sub-dials are a LITTLE bit farther from the center, not perfect, but closer. Still ticks though.
Kingwatch has them on his website, none of our trusted ones have them listed to my knowledge, BUT the ones who source, like Hont can get them for you.
They cost $155