Update!
Okay, as I a posted earlier, i put these on at 12:30 am with an expected completion about 4:00 pm. About 3:00 pm, i was still in the stall phase at 170 degrees. I went ahead and bumped my temp to 300, because i had to have them all done by 5.
By 4:55 most were at 195-198 degrees and ready. Another half an hour and the rest finished.
Total time in the smoker was 17hrs and probably would have been another hour or two if i hadn't turned them up.
So I did another batch of 10 on Sunday, with three of the butts being a lot smaller. About 20 pounds lighter than Saturdays load. I started these at 10:45 pm at 224 degrees. These finished between 2 and 4 pm (15 - 17 hours)
I did find like many have stated that with a full load, the smoker really maintains the temp well, within just a few degrees.
For an upcoming smoke of 12 in a few weeks, I am going to plan 19 hours for completion, and have a cooler ready to hold for few hours just in case.
Hope this info helps some others.
Jesse