I have tried brining, no brining, rub, no rub, and injecting with a rub. The best combo I have found (for juiciness, pork flavor, and tenderness) is injecting the inside with a rub on the outside. If you don't want a hammy flavor, just don't use any sodium nitrate curing salt (the pink stuff) and it won't taste hammy.
Just smoked 2 butts side by side for comparison (one brined and one injected, both with rub) for 16 hours at around 225 and the injected butt was better. Injectors are cheap and generally easy to obtain and I think that is actually easier than trying to brine a 12 pound hunk of meat.
The brine makes it retain more water during cooking due to the salt gradient but a pork butt is so thick that the brine has trouble penetrating anything more than the outer 1" of meat.
Injecting (using Chris Lilly's injection recipe found on the forum here somewhere) was the best result I have had. Just don't put a bunch of crazy ingredients in your injection and it won't cover up the pork flavor at all.
Make sure you keep temperature spikes to a minimum and it will come out juicy and tender every time.