Haven't played Aika and Rift. It was not actually a system per se, but just normal pvp mode. Maybe I'm just too used in PVP-oriented mmorpg, and monsters are just for grinding levels and farming for me now. So unless they add something like random bosses or uber strong mobs, it'll feel boring.
I do hope they add more stuff to spice it up, but I wonder if they would add things I want, the game would become hardcore pvp with some serious grinding. And FATE system bosses would be able to flee to a different location and/or alter monster in an area or would block paths causing serious disturbance to a lot of players like a real calamity.
One reason why I don't touch other free mmorpgs is the graphics. I just don't like the style of Aion, Cabal, or something that looks like that(iirc, Aika and Rift looks the same). I really like how FFXIV:ARR looks but it seems to be not the mmorpg I'm looking for.
But I still have Blade and Soul. I just have to be more patient.