I used to live in Providence and Boston, and would go almost every day to both Foxwoods and Mohegan. What everyone says is true. Mohegan has terrible pen, about two decks to two and a half. Foxwoods is about one and a half. I've seen dealers cut only about a half deck off. One dealer even cut about a quarter off.
When I went moved to Toronto, all my info changed (address/phone). I visited my friend in Boston one day and went to Foxwoods. Before I played, I updated my Player's Card info to reflect my new address. I think that was the big mistake. Seeing that I was no longer a local, the supervisor must have been more wary of my play. I was spreading from $25 to $400 (two hands). I was told that I could no longer play blackjack there. I immediately drove to Mohegan, and within minutes I was told that I was not allowed to play. Prior to this, I had played for years at both casinos. I don't think I even upped my bet prior to being barred from Mohegan. There is definitely communication between the two casinos, I'm sure. If you're barred from one, don't go to the other on the same day, or even month. Wait a while.
Above all, when you get a player's card, make sure you use a local address, even if it's fake.