im just going to state, it's a bit more grindey than say what you may be used to in WoW/WAR. but i guess it's a bit different. in WoW, you grind quests, regular mobs don't give too much exp but quest exp is where it's at. in WAR you can grind mobs for exp ONLY IF YOU AOE GRIND to get decent exp(there is literally ZERO DOWNTIME(unless you die) in this game, so if your group can manage to pull 5,6, 10, 20 mobs at a time and you barely manage to do it...you are going to keep on doing that until you manage to die or something. two rune priests, a warrior priest, and a bright wizard....literally the bright wizard can aggro the whole goddamn area running around spamming aoe while three healers keep his ass alive...indefinitely), the questing is pretty ok for exp, but typically consistently winning scenarios (battlegrounds) yields the most exp.
aion, mobs give you more exp, and quests really only fork over decent exp if it's the end of a chain (in which you literally get NOTHING for prior quests in said chain), and sometimes the quest exp isn't even worth walking over to complete because kill 5 mobs and BAM you already got more than the quest gives you exp wise. but mobs in this game are a bit harder, and from what ive played thus far, you really...don't want to fight more than 1 mob at a time, i mean, if you do, just run.
though that is my experience up to level 22 anyway, ill comment if anything changes later down the road when if i make it.