I went with the brine listed in the original post, for about 20hrs on a ~5lb Boston butt. Then rinsed, rubbed with mustard, and some of a few miscellaneous rubs we had laying around. Went on the smoker at 225 with 3 hunks of cherry and a couple beer can boats of water for moisture. At 170 IT placed in a foil tray with 6oz apple juice, covered, and went back in at 235 (we were doubting it was going to be ready for dinner, and we lost about 5 degrees while tenting, next time I need to reduce the time screwing around with it and not crank up the heat) until 200 IT when we put in a cooler to rest.
The flavor and juiciness of the meat was great, but severely lacking in rub/smoke flavor. I think adding the apple juice may have been a mistake as there was still plenty of moisture coming out of the meat, there was almost 20oz of meat juice in the tray when we transferred to the cooler - drying out wasn't going to be an issue. The cherry didn't seem to want to stay smoking either and we were basically just baking after ~2hrs, next time I'm going to hack the hunks down a bit smaller and maybe try ramping up the temperature little by little to keep the element heated enough to produce smoke.
Overall not a bad first attempt at a Boston butt, but certainly room for improvement. Thanks guys for keeping this thread alive and posting feedback, it'll surely help me sort out improvements with the next try.