One idea going off of what Zell said could be that we're in the sort of "high late medievel" that sort of the end of an age with the old guard trying to keep the age going on as long as possible while the rise of gunpowder is convincing some its time to move on.

The AoS I personally feel would allow for more diverse nations in more areas since comparing travel between the two ages, its not hard to see which has the leg up. AoS would also let the early roots of colonization begin which is something you almost never see in NRPs.

Ulimately, I think both ages have their merits. I just kinda want to see something of a more classic-setting NRP. Also nice seeing some familiar faces ^^