What breed is your pup? I have seen both good and bad from individuals that have tried Schutzhund training. Those that are dedicated to it and have a dog that truly enjoys it seem to do really well, I have seen some dogs that are just as happy and loving as any other dog, but once they are on the field they are in the zone. Then on the other end (an extreme case) I worked with an individual that knew nothing about the sport or German Shepherds for that matter and decided he wanted an attack dog, he dropped over 10K on two GSDs that were supposedly from direct German Military Blood Lines and did about a month of training with them at a local club then lost interest. At that point he gave them no other outlet for their energy so, he had two dogs that knew how to bite and that was it. Needless to say the dogs ended up biting quite a few people, did some extensive damage and were ultimately put down. I work with a GSD Rescue and we get quite a few dogs that are high strung and bite, it is a lot of work to break that habit when that is all they know, so from my experience my only word of advice is don't start it if you feel you might loose interest unless you can provide another outlet for your dog. Certain trainers I have talked to will do a "personality test" with your dog and see if they feel it would be a good fit, if the dog displays too much stress they generally will say its not a good idea.