Charleston has very unique gameplay. It's circular shape and layout make it fun for a team map for me. However, the bonuses aren't very balanced I suppose. Oh, and I'm moving this to Strategy since you seem to have a focus on gameplay with this thread
Thanks for the suggestions guys (and for moving this to the appropriate thread, I wasn't quite sure where to put it. ) Only ended up with 6 players, and chose World 2.1, and it is going well so far. Only issue is that one time reinforcements leads to a much slower game, but I like the challenge of troop management.
If you want a long game then First Nations Americas can be good, You usually get a 1 on 1 in both continents. The issue with this map is that it is not circular. Although you can go from north to south through the ships, rarely does this happen.