I haven't watched any of his shows, but I have read a book or two by him. And I agree with spygirl...it's not an all-or-nothing sort of decision to make. Some of his principles about dog behavior and society are sound...but his methods are often questionable.

Another trainer you can watch on Animal Planet is Victoria Stillwell (It's Me or the Dog). She has the same principles as Caesar, but uses an entirely different method for training. I much, much prefer her methods. But there may be times when Caesar's more dominant/aggressive style would be more productive. As spygirl says, every dog is different. But in the long-run, I think Caesar's methods have far more risks of causing permanent damage to a dog...whereas Stillwell's methods won't damage, they just might not be as effective with some dogs.