The 6.8 has proven to work, but my personal choice would always be a 6.5 for a hunting set up. Up close in combat roles either will do. I just like the bullet offerings in 6.5 in this range of weights, no doubt more choices have come open in 6.8, it's just a personal preference.
I believe if one is pushing long range the 6.5 has a slight edge, how meaningful that is in the field on impact assuming shot placement with bullets designed for game at reduced speeds would have to be compared. I'd not want to get hit by any myself
