I did play this game.
I only got to about level 30-40 at the highest, but what i did play seemed quite fun. Rifts seemed an interesting idea. And the class/soul combo was decent also.
The reason i stopped is there was too many choices of classes/souls.
Its not a bad thing but I struggle a bit with choosing/sticking to one characther.
Wow was bad enough with 11 choices. Rift was torture for me

Between not being able to choose a class/soul combo, and the fact im just a bit bored of mmos, i stopped playing.
But i think it could of kept me playing for quite a while.