I finally got into a co-op halo 2 game today with a family member, he only lives about 50 miles away so the connection was good, however the way it works online really ruins the experiance for player 2.
Frame rate is all over the place.
Movement can stutter even if it's rather good ping/lag free, the network code makes the game drop frames everywhere.
I also noticed that in halo 2 if you look at each other and turn the flashlight on, in anniversary mode you can't see the light shine from the helmet on each other while in classic mode you can, it's another lost detail which was cool, now forgotten.
Not sure if I can stomach playing over halo 1 and 2 fully in online co-op, it feels like a LAN connection being choked.