I love my Furminator, I use it on all of my CSVs and GSD, no bald spots!
I only use it when the dog is shedding though, and the fur is coming out in little clumps, and only on dry fur - I imagine other tools work just as well, but I like the fact that I don't have to clean the furminator as I go, when the shedding fur seems never ending - the fur just falls away. I never use it in other times of the year. My only complaint is that it builds static electricity and gives little zaps that the dogs don't like (like brushing human hair in the winter). As I understood, it is blade like you find on clippers for shaving hair - but I have never found it to "cut" hair in the way I use it.