My wsm's are good at locking in on a temp for hours at a time, but after a few hours they usually start to stray, and any time that I need to lift the lid for things like foiling, they usually lock back in at a temperature that is higher than I would prefer. Also, I cannot remember an overnight cook in which I didn't have to get up in the middle of the night or in the wee hours of the morning to make adjustments.