Thanks for the feedback, guys.
I'm not using them, I was kind of surprised that they were. Yes, he's 13 weeks today, actually. The only time I have is when he tries to run out into the street on walks to chase the cars (yes.. we've graduated from "what are those big scary things!" to "ooh, can I play with them?!" *sigh*). Personally I don't think a puppy that young needs corrections during training unless they're doing something that's going to endanger his/her life, but from a more general curiosity standpoint I was wondering if they were even safe at all, even on older dogs.
I'm near Peoria, IL. I know of one other training place nearby, but I had opted for this one because it was closer and my vet recommended it more (I didn't know anyone else in the area with dogs to ask). So far, I'm not impressed and probably won't be back for obedience, but it's good socialization for him if nothing else.
Also (I'm not thinking about it any time soon, but just to keep in the back of my mind..) when is a reasonable age to switch to a prong for training? I'm hoping I won't have to - trying to go the positive reinforcement route - but he's already a very confident, stubborn, and strong willed pup and he's quickly going to be much stronger than I am.