If you're really serious about it, you should have a separate oven thermometer to target a real internal temp, despite what the oven says it is.
Discussion
True, but some stuff like brisket needs the most amount of time in the lowest setting around 250F. But if the owen sucks, it might take many more hours.
I've noticed that being lazy and keeping my pizza stone in the oven as I use it for other things turns it into a good heatsink and temperature stabilizer. If keeping a stable temperature is the issue, then that can help too. I'd bet people even line the oven with clay tiles.