I use the regular Mach 3.
I have tried Mach 3 with Gillette Series Shave Gel and I can get 3 shaves out of each blade.
When I try Mach 3 with bald guyz shave gel I can get 6 shaves for each blade. So the moral of this story is if you
get a good shave gel (like bald guyz shave gel, which is probably the best out there) you will be able to use the same blade for more shaves, with no cuts & no irritation.
I hope this helps.