Since got the promotion for the 100% bonus badge, i have been maximizing my time to level my MA, DOC & MUSE. After painfully level'ed my doc to 20, onwards to 30 is really really boring & painful experience.
doc is weak in physically attack, limited mp and worst not build to solo play. Lucky i managed to buy a metal pet at level 17 (now 18) to level up with. Set pet's xp % at 25%, i am able to level doc pretty fast.
after spending sometime level'ing trial, i can say whacking mob ard your level (+/-1) gains faster in experience than hitting mob At higher level (>+2).
the finding was when i hit a mob higher, my attack becomes weaker hence gain less. i hit a lv23 mob when i was Doc at lv21, my overall xp gain is 2.15% with each rest. but when i hit the mob at lv20, i gained 5.23%!
so that is why i think i should share with all players.