I do think a medieval era could potentially have some interesting action, and I wouldn't mind basically swapping out crusading and religion with the exploration of the new world side of things. But at the same time, I don't really want another age transition necessarily. Although if you did make the age transitions as semi-optional, then maybe having another era wouldn't be that bad. So I'd maybe stick with the Mayans through the first couple ages before swapping out to someone else for the new exploration age. But some other game I'd want to go Rome-Norman-England.