Grand Fantasia is similar to Eden Eternal, but has been out much longer (over two years) and, to my knowledge, has a fairly decent player base in terms of numbers. On the other hand, Eden Eternal is new and one of Aeria's other games (Kitsu Saga) is shutting down, so it's getting a lot of attention.
The only problem with Eden Eternal is, at the moment, it's extremely easy to level. To add to that, there's not much to do once you hit the level cap (50) except for farm gold and/or level other classes; you have access to multiple classes, though some have some prerequisites that must be fulfilled in order to unlock them. However, a new race is coming soon™ as well as new content, which includes access to new dungeons, zones, and an increased level cap (this allows access to the next class, which is the Warlock).
With that said, I think it's worth giving Eden Eternal a shot.