My father received three Mach 3 disposables (not the cartridge kind) two years ago as a Christmas present. He has been using them since and is on his last razor now. I also noticed on the Gillette India site that their average usefulness is rated at 7.9 weeks. I am curious, has anyone shaved with a disposable razor for eight or nine months like my father has? He shaves at least twice a week, if that is any indicator. If the carts last that long as well, I can understand why people pay for them (but likely not me).
If it helps, I haven't ever used a Mach 3 or any type of cart, but I don't get more than two to three shaves from a razor blade (four to six from a DE because it has two shaving surfaces on it). I personally have used a DE, several electrics (which work for about a year before the blades get too dull to shave) and disposable Bic razors. I tried a twenty for a dollar three-blade dollar store brand once and they were terrible even on the first shave due to dullness (I assume the Gillette and Schick versions aren't like that). Other than the electrics, I never get more than three shaves out of a razor blade.
If it helps, I haven't ever used a Mach 3 or any type of cart, but I don't get more than two to three shaves from a razor blade (four to six from a DE because it has two shaving surfaces on it). I personally have used a DE, several electrics (which work for about a year before the blades get too dull to shave) and disposable Bic razors. I tried a twenty for a dollar three-blade dollar store brand once and they were terrible even on the first shave due to dullness (I assume the Gillette and Schick versions aren't like that). Other than the electrics, I never get more than three shaves out of a razor blade.