I don't want to level but rather I want to be rewarded for playing the game via skill advancement. I am an old school UO player from 98, shadowbane also and have played many MMO's over the past 17 years and personally the most rewarding experience was the skill based system from UO.
The only downside to that system that I found was that after you had played the game and the newness was gone and you just wanted to start a new char and get up to a competitive level you had to macro. This became quite an endeavor in itself and gave a great feeling of accomplishment when you finally hit that 100 / GM Status in whatever skills you were macroing. If that same sense of accomplishment could be achieved without the macroing through gameplay i would find that to be even more rewarding.