Server is lacking active supports right now, there is an over population of dd's but feel free to play whatever you want, just take in consideration that mages have a hard time finding raids.
About population? EU prime is the best right now because you can find raid bosses party everywhere, there are a lot of russians leveling up alts or just new players. And about na prime? Well NA is just dead to me, you can use this time to solo farm or afk fishing.
I consider myself a new comer to, i just have five days playing here and already have my sws 45. Server is good and it seems it get better the higher lvl you are. Try by yourself.
Have fun.