Thanks, JMA. But I would definitely not consider myself a master mechanic.
Yes, I've built one vehicle from the ground up, chopped a few, sectioned one, and modified a whole bunch of them, but that doesn't exactly make me a mechanic, let alone a master one. And I have yet to rebuild an automatic.
To me it's simply more rewarding to do things myself, and when things go wrong I can blame myself, which I much prefer.
Also, I don't mind spending 15, or even 30 minutes, to get a tire balanced to perfection. A tire shop can't really do that.