Ok here is the deal
Get a lvl 70 friend that is able to solo Hellfire Ramparts(many ppl do it for money) to "boost" you
I was getting 680xp per mob without rest, and around 1200 from bosses
When i dinged 56 xp started to raise even more
Its not a major thing but u can slack lvl up that way, u only need to convice a friend its worthy solofarming Hellfire Ramparts for gold