I go on average to the Borgata once a month and usually play $50 blackjack. I remember reading/hearing somewhere that the comp formula changes when your average bet is $50 or higher. (And it seems to be the case, I've earned substantially more playing $50 hands than $25 hands, not just double the comp points).
I've noticed the room comps getting a little tougher. Any other black card members notice that some Sat night comps aren't free anymore? Granted the rate is drastically reduced but there used to never be a problem booking it advance at no cost.
I guess with the economy the way it is, more people are going to AC than making Vegas trips. And it seems to have led to more Borgata gamers - even if they aren't betting as much. So it's like there are more rated players competing for the same amount of comp rooms.
Regardless, Borgata is my favorite place to play and stay.