According to what I've read, X-Plane Revolution comes with :
- A realistic flight model,
- 35 kinds of breakdown,
- A real weather forecast management (so you can use your METAR & TAF knowledge ),
- Hundreds of planes downloadable for free,
- the entire world modelized in 3D with thousands of airports available
Quite the same offer as Flight Simulator but it seems the resolution we obtain in FS through the use of meshs (especially VFR ones), is the default one in X-Plane Revolution which comes on none the less than 7 dvd and will take initially 60 gigas on your hard-drive !
With all the mesh I have on FS I'm gonna stick with it for now but when FS2008 will come I won't forget to look the challenger...
Look these pictures :