I think the flavor of Pathfinder can't be beaten. Flavor is what drew me in. But can flavor alone sustain it?
I know some folks like CoL would be happier with a more drastic overhaul. In some ways I wonder if Crusader wouldn't be happier with 4E. But then again [to quote the Incredibles], "If everyone is super then no one will be".
Crusader made a pretty good point when he pointed out what a balancing factor it was in 1st edition that different classes advanced differently. 2 characters with the same amount of XP could be completely different levels.
Should balancing decisions be that simple or should every class be ubered to the same degree?