Well those organs aren't needed if you aren't planning to breed so I think its best to remove them while the dogs are young and healthy. IF they get testicular cancer they might not do so until they are seniors and then perhaps the procedure would be more risky. Also, cancer spreads and grows before you even know its there. By the time you catch it and try and have the dog neutered to take the cancer out, it may not be completely removable.

Also, I wonder how much you socialize your dogs. People come into the dog park all the time with unaltered males and they say their dogs aren't aggressive. But have unaltered male dogs in the park ALWAYS seems to cause trouble in the group. Even if that particular dog isn't being the aggressor, his prescence is hyping up all the other dogs. Even my spayed female shepherd will start her dominant act when an unaltered dog is around. I hate when people come in with unaltered dogs.