I got one of these razors as a gift a few years ago. After seeing the commercials I wasnt impressed but hands down this is the best razor I have ever used. I have a tough beard and have always had problems with razor burn, no matter what technique, gel or brand of blade I use.
All that changed with this wonderful product. I am still using the original battery ! Which intially was a concern for me, having to buy batteries and blades. The only draw back may be the price, I think its about $11 for four replacement cartridges but its well worth the money. I shave every other day and have to buy about 3 packs of replacementblades a year. I get a smooth shave even after the wear indicater saysits time to throw away the blade.
If you have a tough beard and dread shaving, give the Gillette Mach 3 Power razor a try !!