Just want to toss this out there.
Because I work nights, I would NOT currently be able to host any group hang although once my work schedule finally changes its all game.
Umstead park has some amenities which might make for a nice hang. I wouldn't want to encroach on the Smoke'd Butt hang or the Uwharrie hangs though.
The reason I think Umstead could be cool is that it would be fairly easy to take advantage of the trails in the park and have several options for day hikes that could be anything from a few miles, or much much more if one really wanted. All loops mind you. I like loops.
I would say the best time of year for such a hang would probably be during the non-buggy months, perhaps even winter if there isn't a local hang around that time already.
The big catch I think would be camping. There is a cheap primitive tent site that has a NICE fire ring, a few picnic tables, running water a small park grill and an outhouse. I've walked through here and it would be fantastic for hammocks, though I have no idea if they are allowed in the park. The other catch is a 25 person limit.
Aside from that, we'd be restricted to the general campground. I have no idea what the tree situation is there.
There is a 'group lodge' that will hold another 25 people. Its would work out to less than $2/person and its only a few minutes walk from the primitive site. Of course, what crazy talk am I thinking about, there's no trees inside a lodge.
There are also some VERY nice picnic shelters which would make fantastic area's for a cookout, but aren't close to either campground. This one will accommodate a whopping 125 people.
Anyway, there's some really nice hikes around this park, though it does get rather busy on the weekends, but it seems a shame the other hangs are close by, but ignore possible opportunities here.
I'll have to deffer to the more experienced group participants as to how suitable to actual amenities would be.