Your first 50 will likely be done by following the main story/sidequest chains with some "grinding" (basically there are unrelated monsters in your way so you kill them) on the way. After that I imagine it'll be a lot like it is now with leves/behests/parties. As long as they at least try to have quality over quantity for their leveling quests then it'll be okay. If it's just WoW style "Hail adventurer! Blah blah blah bring me 10 bear asses" then it'll actually kind of suck. Yoshida's team hasn't really messed up that badly though other than a couple things so I'm not too worried about that.