I like my Mach 3 pretty well (although the battery is silly). But you MUST:
RINSE THE BLADES FULLY EVERY 2nd or 3rd STROKE!!
Ever since I started that, I get 3 weeks out of each blade.
I think the bigger-biggest culprit in sub-par standard shaving processes is the crappy gel creams Edge and Gillette sell ... but this new stuff is AWESOME!
Three varieties depending on your skin. TRY THESE!!