Be forewarned that the best part of the site, the mosaic, is covered up for all but the high season to prevent damage. It's possible to have snow up here on the mountain until early Spring too but that wasn't closing the site or stopped any sightseeing. The paths are easy to follow and the descriptions are quite good. The other highlights are the theater, facing away from the mountain but more on the average quality, the music hall in general with the mosaic and I think it was the bathhouse with the columns in front.
Cheap entry and close to a main road should make this an easy visit but I can understand that it's not as popular as others.