I've noticed lots of issues with the game chat. I've had times where all but one person can be heard, or player 1 can hear players 3 and 5 while player 2 can only hear 5 and 6. I, and several of my friends, have also noticed audio issues within the games music or sound effects while using game chat, but not while using party chat. I played the VoG the other night with no gunfire sounds from the vex (except for explosions).