I am assuming there is a list of what is in "GA" and also what is new whenever it is updated but I can't find it.
I have used Overlay Editor to convert whole areas from old FS9 airport scenery - doesn't look great on X-Plane but gives some detail until/unless there is a "GA" one to replace. I did see a post on this in 2014 but it was a customer who made a list (now of course well out of date)