Looking at the cost for the small additional scenery, and the cost for the Maule and Mustang, I can say while I might try the free version on a whim, I will never become a frequent user.  I hardly ever can justify spending money to buy a payware aircraft now, and only have a few in the hangar.  Not to mention, I highly doubt MS's aircraft will be anything better than the default aircraft in any of the prior versions.  Certainly not the payware quality that you can get from many developers, including Eaglesoft, Carenado, and Aerosoft.