Yes, the 6s 5-speed is apparently only like 5-10% of what Mazda is building, so when the exact car I wanted showed up in VT, I jumped on it... I probably could have found it in MA or even NYC area and saved a few hundred bucks but I liked being able to check it out and sleep on it for a day.
The 5-speed is sweet, somewhat of a short-throw... I'm still taking it easy on the engine so my shifts aren't silky smooth yet, but the clutch/tranny just feel "right" - an easy transition from the Mystique, unlike other MTXs I get into and have to take some time to learn their feel I felt right at home in the 6 the first time I drove one.
GTO = compelling but dealers will probably mark up
Maurader = nice but I think they're overpriced and will probably depreciate fastest of the group
Mercedes C320 - NICE but not a lot of car for the money
all your other choices are rear-wheel-drive, I don't know if that's an issue for you, but for me, the 6s was the no-brainer choice in terms of performance, value, and practicality.
PM me if you have any specific questions... but I've only driven my car a half-dozen times to the tune of 100 miles. I'm away on business and will be gone for 2-3 weeks, so I hope my car is still there when I get home

-Peter