I have a PS4 and my friend has a PS3. We would really like to play together. I understand that this is not enabled because you don't want players to feel that the people they are playing with have an advantage/disadvantage; while this makes sense in competitive multiplayer, in coop this is much less of an issue. At least for the PS3/PS4, the difference in graphics is not great enough to substantially affect noncompetitive gameplay. Do you agree? Please weigh in and let's let Bungie know we want to play with our friends.