On Saturday, I smoked my first pork loin and it took just under 4 hours for an IT of 145*. I had injected it with apple juice and Dale's marinade, applied pork rub and let it sit in the fridge over night. It was delicious and my son and his friends feasted on it after letting it set for an hour and a half foiled in a thermal insulated bag while I traveled to my uncle's lake house where the boys were fishing. It maintained the IT of 127* an hour and a half later before it was sliced and served.
I, too, smoked my first butt yesterday (Sunday). The first mistake I made was not reading this site. I knew the 4.5 butt was a little thicker and would probably need to cook a "little" longer, so I put the meat in the smoker at 1pm. I then started reading this site to realize that this should cook to a higher IT (185 for sliced or 205 for pulled). It was 8pm and my kids were starving, so I pulled it at 185*IT and sliced it. Some portions were very tender and actually started to shred when I cut the meat. I foiled the remaining portions of the butt and put it in the smoker and raised the IT to 205. I pulled it out and let it sit for another 30 minutes. When I opened the foil, the difference was amazing. The meat simply fell off the bone. I had no idea that 20 degrees would make that much difference, but was pleased to do so. I cooked the butt at an average of 275*, which might be a little hotter than normal, but I was trying for get that IT up so my kids could eat.
Lesson learned -- start earlier.
I promise to take pictures in the future!