/played on the Druid - 1 day, 20 hours, 33 mins, 24 seconds
With the new Refer-a-friend there are 2 benefits :
You receive double XP if grouped with your "friend" on mobs and quests.
And secondly....For every 2 levels your friend gains they can grant you a "free" level.
The XP is insane and the free levels are nuts !
It only lasts until 60 so I've slowed down quite a bit but it makes the grind to 60 decent instead of down right mindnumbing.