I have 2 (now) teenage sons. We actually fought D1 as an xmas present years back for the older one. We used to always play together, had a consistent 3 man fire team. One totally lost interest after the Y1 debacle where all the guns got left behind. The other dropped at D2 because the game back groggy and slow, and all the weapons are very meh. I don't know who D2 was made for. It doesn't suit any of the play styles we developed for D1, and seems to be a huge step back from the original.
Family fire team. Awesome.