Hey! I'd buy from whoever has the longer return policy. Best Buy is 14 or 15 days now. That way you could exchange for a new unit if something is off. Don't know if you are still looking but I was looking at a deal over at dell. You get a game and a $100 dell gift card, may make it comparable to the refurb price. The bad thing is the $100 gift card expires a about a month after they issue it, but you could buy some accessories or a couple of games. Looks like it ends tomorrow.
This was the one I was looking at:
Xbox One 500 GB Console - Pick One Game: Rare Replay, Gears of War Ultimate, Forza 6, OR Rise of the Tombraider