My Ratings:

Classic- My first ever server, seems pretty decent. You'll get fun if you have friends. Quitted
Era- My second server ever played, it is really developed and have some good staffs and developments, its just the community and prices and jobs. Quitted
Zone- Almost 1k hours, quitted, it was fun when it was low player count yet fun too in big playercount, big changes, decent, yet, never found any exciting quests. Too me, it was too much, it became boring ever since the big change.
Delteria- has a potential, just need to be out in iOS