"We saw a lot of things from the Saints that we haven’t seen working against ourselves. ...They do a lot of things well, so there were a lot of things that we were able to evaluate and also adjust to. We can walk through them, we can talk through them, but it’s different when a good team does them and hurts you with them and you have to make those changes," said Belichick. "(There's) no better preparation for a game than working against the team you’re going to play. We’ve seen a lot in the two practices yesterday. We’ll see a lot more today. It’s been a great learning experience for our football team, not just the players but our staff as well."
It certainly seems to help that there's a friendly relationship and respect between the coaches. If the tenor is competitive and mutually beneficial but not bitter, it will work.