It was really good. Surprisingly good. And really odd to be eating a chuck roast cooked to medium rare that was tender. I need to work on the seasoning. Will take some experimentation, because the sous vide can intensify some flavors. Also, I don't generally like to add salt during the sous vide, because you end up almost curing the meat, which can pull moisture out and make it dry. Sort of a balancing act.
But the main thing is that the technique worked exactly as intended and the meat was perfectly cooked. Just need to tweak the seasoning. Next time, I'm going to use some whole fresh herbs in the sous vide, along with a little compound garlic butter. Then a nice herb rub before searing it with a healthy amount of salt... like cooking a steak.