I have now rooted and am reading through some of the stuff on ROMs, but am having a bit of trouble finding what the major features of a given ROM are. I am using Launcherpro which gives me all the user interface stuff, and I would assume I would be using the same launcher with a custom ROM, so what type of "under the hood" features do the ROM's have in general compared to a rooted phone with stock Froyo and a decent launcher?