Review (3/5): Upgrade to the Mach 3 for a better shave, easier cleaning, and cheaper cost per week.
I have used these razors for about 3 years. I'm a dry shaver, so a good, sharp razor is very important to me.
The one really big fault of these Customplus blades is that there is no place for the cut beard to go, so it packs in between the blades. (As I dry shave, I simply tap the razor on the sink every stroke or two to keep it reasonably clean.) The Mach 3 and Fusion have the open backs, which are almost self-cleaning, so I prefer that design.
Each razor lasts me a week. The first shave is great and the 2nd and 3rd aren't bad. 4th to 7th get worse and by the end of the week I WANT a new razor.
When I first became aware of these a couple years ago, they were priced at about 20% of the price of a Mach 3 blade. Now in 2014, they are about 1/2 the price of a Mach 3 disposable. What has happened is that the price of these razors has doubled, while the Mach 3 has stayed the same or even come down a bit.
Now the Mach 3 is a great blade, and I can get 3-4 weeks out of one, with a better shave and easier cleaning - all at the same cost per week, or even cheaper. In my opinion, the Mach 3 is at the best cost/performance point.
The Fusion? I used my initial blade for a whole year, though I have to admit that sheer pride kept me gritting through the pain through the last few months. The replacement blades only lasted a month or two before I couldn't stand them anymore. In my experience, they are still way overpriced compared to the minor increase in performance over the Mach 3.