Just finished my 10th GEM Stainless blade for my Micromatic Open Comb. I got about 15 shaves out of each. shortest was 6 but I must have done something to it as that was the only exception. other than that 12 was the lowest, and todays 19th shave was one shave too many, not horrible just not nearly as comfortable.
Generally shaves 3 or 4 through 10 or 11 are the best, and then it just kind of gradually fades away into gentle tugging and mild razor burn.
Gotta say using the GEM MMOC with a stainless blade is the most comfortable shave Ive come across. especially in the sweetspot of the blade.