Pro tip for braisers out there: There's too much variation in oven behavior to recommend a temperatures below 300F. Some ovens, for instance, will dip too far below the specified temperature, causing the beef to take several times as long to cook. So, most recipes recommend higher low temps because they expect your owen to suck.
Discussion
Use this
Meat thermometer is a must. Every oven sucks differently, every cut of meat weight and shape is different, but core temperature is only one.
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.
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.