When I made my first route 2+ years ago I would have liked to use decals, but back in those olden times all such tasks (importing DEM and so on) was a long-drawn-out learning process (at least for me), so I didn't use them.
Yesterday as I was toying with a new route I decided to bite the bullet and start up the learning curve to use the new Google Earth overlay feature in TS2014. But there is NO learning curve! You simply get into the editor for the route and click ctrl-g. Bang. The decal-like overlay appears, and one can easily choose different varieties, different opacities, and so on.
RSC gets a lot of criticism at times, but dang they deserve some bigtime praise for this feature. They just keep making this simulator/editor better and better.