The EXP issue with bounties is going to be addressed and fine tuned because being able to power level this quickly, defeats the purpose of even having levels 1-60/70.
In a co-op game, the game host determines the level of the monsters. So you create a new level 1 character on an account that already has Torment difficulty unlocked. This new character hosts a game (thus all monsters are the same low level) with the difficulty set to Torment VI (to maximize the bonuses), invites or has at least one higher/max level character join the game, do bounty’s, and reap the experience gains (if three other high levels do their own individual bounties, this maximizes the experience and reduces the amount of time it takes the low level character to ding levels – there’s a point though where the higher level characters will have problems killing monsters since they are leveling as well and scaling with the difficulty setting of the game).
