From what i'm seeing, the guild, and the rest of the interfaces, heck the rest of the game itself, is a mashup of GF/KS.
So for some, you will feel at ease, for me, it's spells boredom fast..
It's cool to only make 1 character, than you can have access to all classes, then your drops will/might be useful to you if you are constantly switching classes..
As for me, I'm sticking to lvl mage/cleric, as these only are a pain already, wasted time to unlock warrior 20(Knight 10), but i tried hunter, even i'm not too fond of them, i still enjoyed it, and the thief is very nice, change of pace from long-range spells, plus i can't wait to see to Martial Artist in action, heck Blade Dancer ^^
So, it's fun.. for a while, but the game makers, didn't spend lots of time doing this game. Reusing the wheel is good, but if the only thing that change is the class system, you won't stay long afloat ;-p
*that is purely my humble opinion