Quest are 100% fine. As long as the whole leveling process is not SOLO! that is the #1 issue in all western mmos atm. Outside raids/dungeons everything is solo based. Instance grouping is NOT ENOUGH.

The only problem with quest leveling in most mmos is it is pure solo based, which is stupid. Make them soloable, make them give a bonus for completing with groups.

I think a game with a good group questing option as well as a solo one would be a huge win.