Bo, I did a 7.5 lb'er on low and slow today. Wish I'd took pic's of the process.
Bottom line is that I put it on at 9:30 AM and took it off at 6:00 PM using water in the pan with an average cook temp of 255*F.
IT when on the grill was 46*F Finish temp was 172*F probe tender. Pulled off the WSM and foiled and wrapped in a blanket for one hour to rest. Right now it's in the fridge to be pulled tomorrow.
I've located a local source for BP and can't wait to try it after reading your other great posts. I too would like to shorten my cooking time as I'll bet I'm older than you! ;D