What i never see in this kind of discussions is my reason why i will always stay on an at least "high" population server.
The MMO feeling. I enjoy the game infinitely more when i zone into a hub full to the brink with players. Or seeing hundreds of players fly in to a boss fate from all corners of the zone. This has no gameplay value but more a immersion and cinematic value. I feel this will be lost on a low pop server, and i hate nothing more than seeing no other players around. Even if i don't interact with them.