I didn't, no, but if I take one of the gearboxes apart again (we have to strip down the robot at least once more before the champs so I can do it then) I'll make a video/take pics then. In the meantime ask if you have any questions, the past year of fighting our own motors has taught us a lot about them!

Also yes, the higher the voltage you run the more efficient and the greater torque. Though be careful with the 24v ones, I may be wrong but I think I have read something about them being the wrong shape to fit into a gearbox off the bat. That may have been GR02 specific, I'm not sure. The 12v and 18v models go in like the originals.