I think you guys who are not getting great results on the bottom round are doing it for too long at too hot of a temperature. I started out doing it for 36 hours or so, but was not happy with the texture at that point. 18 hours or so is plenty.
And 140 is too hot, unless you are very opposed to any pink in the meat.
Mine turns out tender and very flavorful. It’s my go-to cut for sandwiches and such.