Well, I started maybe a month ago, and the first profession I took was Mesmer. I play a condi mesmer, and I’d have to say it’s fun. It may not be the best in the game, and heck, I’ve probably screwed my build ( I use Carrion for most everything) But I haven’t had a problem with dealing with enemies.
Although, with Carrion I may be considered a tank, given my lvl 80 mesmer has ~25k hp so I just pop down my phantasms and keep up the torment/bleed.
Personally, I followed my own path to a build, and I’ve had lots of fun as a condi mesmer.