I can't speak for Sunshine as I haven't looked at their conference much (although the most recent champion is from Sunshine and they appear to have some solid teams right now), but I can tell you CCAA and GLV are not for those looking for the easy road. They are the type of conferences where you could legitimately have a decent team and not make the NT because you have a losing record.
What I can say about CCAA is about half our coaches have been in the conference over 30 seasons, with a few of us over 50. We have a pretty tight, but competitive group. Not sure if the other 2 can say the same, but I don't think you'd go wrong with any of the 3.