Max your Marks too, they'll turn into commendations on 9/15 allowing you to get vanguard/crucible packages...which I believe come with XP. I'm not going to do anything with bounties or public events though, not too worried about getting to 40 super quick. Plus I have a ton of Focused Light. I'm gonna try to stretch out the TTK as much as possible so I still have stuff to do in-game. I remember in TDB & HOW I was done with everything in about a week :/