I don't play BJ, but much prefer MS to Foxwoods for gaming. Foxwoods has no "feel" to it. It seems like a huge gambling factory. I like the look and feel of The Sun much better.
Depends on your game. Video poker is better at Mohegan Sun. At both places, table games run in the $15 to $25 dollar range on weekends, with a few scattered $10 tables here and there midweek.
Mohegan has a better choice of shopping or dining, and the lay out of the place is much more user friendly than Foxwoods.
I haven't visited either for a while, I usually play at Twin River in Lincoln R.I. instead. Although their video poker is horrid, but penny slots and video keno is decent there.
MS uses 6 deck shoe, FW uses 8 deck shoes. I was told last year that FW converted all their tables to H17, but MS has not. In general, I think MS is beautiful and FW is, well, ugly.
Caveat: I am not a high roller, so don't know how high limit BJ may differ between the two. --Joe