I use the carbon blades from CVS. It's just about a half mile from my house. OK, I buy there because its close to me. Seems here lately on occasion I'll get a pack of blades and maybe there will be a good shave for one or two shaves then the blade edge goes to crap. I am thinking the machinery that grinds the blades has gotten worn. And the machine operator has let it go and not changed the grinding wheels. Now the next pack may produce 7 or 8 good shaves before I change blades. I am curious if anyone else has run into this? And yes I have thought about ordering a 100 blade count box. However, what if I ran into the same problem with the 100 count ? Thanks for your response.