If you managed to cook a 17lbs brisket through in 7.5 hours (even pre-trimmed), you were almost certainly cooking too hot. I usually smoke at 225-250 for ~45-60min/pound. It's not unheard of through and if you're happy that's what matters. I would recommend getting a quality thermometer and cooking to temp to be safe 195-210.
Definitely agree on the salt and pepper rub. If you want to kick it up a notch rub the salt and pepper on 24 hours before your cook and let it set in the fridge.
Edit: I see now that you have one of those Bluetooth thermometers in it.