This is by no means intended as a flame, just some observations on how FMS compares to the $$$ RealFlight simulator.
I'm trying to learn to fly an R/C plane, so I set up FMS to help me get started. I found the software works great, does amazing stuff, and has super support for adding my own transmitter.
But somehow I didn't seem to be getting any better at flying the real plane. In desperation, I finally broke down and bought RealFlight for $200. It includes the "transmitter" and an interface to your own radio as well, but this is EXPENSIVE software.
My first impressions: the backgrounds are more photo realistic. This wouldn't matter except that it holds the interest of a lamer such as myself better. Little touches like smoke from the plane make the flights more fun too. There are many more obstacles on the default flying fields, both to dodge and look at.
It also includes a "Virtual Flight Instructor" which shows an instructor and his plane performing various maneuvers. You can fly along if you're good enough.
And there are games like "pylon racing" and "limbo" to keep the pilot amused.
I guess what I'm getting at is all these apparently needless features add up to something that holds a beginner's interest better than flying around a blank sky. I had thought that RealFlight would only be of interest to expert fliers intent on customizing the zillions of controllable options for flight and scenery, but I think it has appeal for beginners as well.
Oddly, I don't think the planes in Real Flight fly one bit more realisticly than those in FMS.
I'd be curious to hear what others think.