We've also stayed at MBYC (Little River), Osprey (Socastee), St. Johns... as well as McClellanvile, Ashley in Charleston, Port Royal Landing (I think before SH ownership), Beaufort Town Docks (before SH ownership), and at the Harborwalk in Georgetown. We spent last winter at Safe Harbor Charleston City.
I'm not so aware of the surrounding areas, aside from downtown Charleston and Georgetown... but the marinas all have pros/cons. For instance, Osprey has been very inexpensive and is very well-protected... but also relatively isolated, so ground transportation can be a thing. St. Johns is indeed a bit exposed; ditto Port Royal Landing. And we survived last January's storm at SHCC -- because we were on the opposite side of the dock from S winds, "inside" the original Megadock" -- but many boats on the outside got beat up, trashed, a couple actually sunk... Et cetera.
Charleston is of course the most "social" of those. Easy access to a nice town with lots of stuff to do/see. Very well run marina. OTOH, if your SHCC slip assignment is way out toward an end of the original Megadock or the new Megadock... just getting off the marina grounds can be a tromp. (Or we could call for a golf cart...) I think if we were to try SHCC again, we'd maybe only do it if we could get one of the inside non-Megadock slips... which have in the past mostly been for all local boats. Or maybe we'd try again for an inside protected slip at Ashley, just next door.
Beaufort was pleasant. Only happen to have stayed there once, though. Nice town, docks not great, at the time. Might have been other options in the area.
We do like our visit to Georgetown. Nice downtown. There are other marinas there, of course, but Harborwalk is so convenient to the downtown area that it's been our go-to for when we've passed through there over the last several years.
-Chris