I really like cooking arm roast. I have cooked them to 200+ rested and pulled them, I have cooked them to medium rare and sliced thin like a tri- tip too. One other method I might add is smoking to 150-160 and then foiling with a little beef broth until 190, Then slicing thin and serving the slices in seasoned beef broth. I put this style on hoagie buns with onions, peppers, and provolone cheese and called it a "smoked philly." They got rave reviews at the party I served them at.