Just stack XP gain if you really want to power level. You can easily get up to 50% more exp on some rare items and blue ones. Wyvern had 60% extra exp gain on one stage.
It was actually 80% :P I was leveling to fast, so started looking for other stats. Btw how the heck can I boost my crit %? I have only 5% crit chance at the moment on my wizard but I NEED more!
Nine out of ten voices in my head say I'm not crazy. The other one is humming the Tetris theme \o/