I'd keep the CX7 GT if I were you. It's probably the coolest looking, most fun to drive, non-luxury brand SUV out there. Plus if you have the 2.3 turbo engine, that thing just hauls.
The MS6 is a fast car, but it's still a boat of a car. But hey, anytime you get a Mazdaspeed, you get points for exclusivity.
The CX-7 is already gone and while I did enjoy it, I had an 07 and because it was a first year there were some things about it I couldn't deal with. I was going to re-up and get the 2010 model but they weren't doing deals on it at the time my lease came up so we went with the new 6 because my fiancee is the one driving it 95% of the time.
I'm working on the sell of trading in the 05 6GT we own, to upgrade to either a Speed 6 or Legacy GT Spec B. Have to wait for the wedding to be over so nothing's happening until at the earliest the end of this year. I just know I'm going to miss having the AWD...