Since this is your first butt, I would cook it normally (rub and smoke). After you sample it, make the additions/corrections for next time.
Or...since Stater Brothers has butts for 1.49/lb this week, buy two and inject one. Then you can compare the difference right off the bat.
Dbl Bbl Smoker, UDS, ECB, Char-Broil gas grill & charcoal grills, SJ - Certified Moink Baller