Wow, thanks for all the great info. Boston - you've got the place nailed. I'd checked into Masterpeace and had called and made a reservation to come in, but the other place was recommended by so many people, we switched. I'm at the very bottom of Boston, so Franklin's not too far.. Maybe we'll try going to MP for their saturday morning social just to check the place out.
Last night, spurred by all your help, I convinced DF to return the shock collar and we did a little training "my" way. It worked but wasn't quite as effective, so DF was feeling a little cocky. But he really does want to do the right thing.
Judi, DF does actually have a bit of a mean streak - I think it comes with the paramilitary background.. training to him is SERIOUS business, I kind of doubt he got a single "good job" in marine boot camp and he just doesn't think that's any way to train.
He's also had rotts before who had more of a "typical" temperment and needed a firmer hand.
I appreciate all the advice you guys have given me and your willingness to read my post! I'm sure my dog will benefit greatly from your help. I'm having a lot of fun reading everybody else's threads and I'm so glad I found this place.