AP is on Shii-Cho server. It works fine for people from the whole World.
(Some members may have alts on some others ervers for personal reasons but Shii-Cho is the "AP server").
Shii-Cho is a PvE server (you won't be ganked anywhere, or during a trip or a quest) but you can PvP actively in warzones.
Shii-Cho works well for US and European people and also for Australia: we currently have people from all those locations and we have NO ISSUE at all.
So far, population is good during the day GMT and even heavy during the night GMT.
Waiting queues happen but we never had big issues (it's like 5 minutes), except on launch day.