A big difference in scenery design between FS9 and FSX/P3D, is the ability to create a custom 3D model for the terrain instead of interacting only with the FS mesh. And this point is key to enable not only a high precision of a mount, but also to apply high definition textures on the slopes. This new technics prevent from blurry visuals, remember how look the Grand Canyon in Colorado in FS9 for example.
That’s one fo the feature also used by Real Earth X in the Italian Dolomites for FSX and P3D. Their new scenery models Zoldo and Pelmo. Have a look also on their bundle solutions to get a bigger phootreal area at once, it’s a nice deal.