No idea about servers.
I tried it for a week or so, it was OK. I leveled and did some quests. It's very much like WoW, but I didn't find Rift as immersive. I didn't enjoy the music either, the graphics were nice though.
I didn't level enough to do any dungeon or raid content. The rifts create spontaneous groups and there is not much social interaction. People get into the rift, close the rift, collect the loot and leave.