I love 2-doors and I think that 2-door Mazda6 looks great! I've never owned a 4-door in my life because they just aren't nearly as good looking IMO. The 6 was the first 4-door I have ever really considered, simply because everything else is so great about it. But if they made a 2-door like that, I would never consider a 4-door.
I don't know... The coupe is cool but two things always turn me off of coupes. First, the insurance always tends to be higher because its "sportier". Second, try fitting adults in the back of the coupe... It just doesn't work as well as the sedan (obviously). Since I tend to travel with herds of people, the sedan is more for me. It truly is a per person type thing.