I couldn't agree more with RdKnB. I've got the exact same smoker, but just two weeks longer. Done pork butt in the past and been in the same spot you've been in. Hungry people and meat not quite where you want it to be.
Here's what I've found out, pulled is the easiest to do the day before, or over night. The only problem with over night is get up every hour to keep the smoke going.
Last time I did butts, I set my temp at 250*, my MES windowed 40" runs about 20-30 lower than what it's says. I've checked it with three different probes. So you really need to check it independently of setting.
If you're looking for that sliced pork then yeah go to 185* nice and slow, that may take 12-15 hours or longer.
I do mine to 200 (even to 205) but after they hit 165* I wrap them, and leave the temp alone and wait for them to hit 200. Then double wrap them in HD foil and put them in a cooler with lots of towels. Last time I got there in under 11 hours.
Then I went to bed and got them out at 9 hours later, still almost too hot to hold on too, and I will tell you they were the most juicy and tender butts I've smoked.
It's just what I do... and will keep doing. Just don't give up...
Here's one of my rubs (all measurements are approximate, change to your liking)
1/4 cup brown sugar
2-3 tbsp paprika
2 tbsp CBP
1 tbsp cayenne pepper
2 tsp dry mustard
2 tsp onion powder
2 tsp garlic powder
2 tsp thyme powder
2 tsp sage
2 tsp coriander powder
2 tsp rosemary