I want to say : a multiplayer mode where the player can configure it's own game-session with the choice of playing against bots / real people, choose the game mode ( relay, pro mode, pistols only, etc ... ).
It should be great for those who don't like "real" multiplayer, those who want to train the maps, etc ...
Moreover if such a game-mode could exist, of course, no XP coulb be win on this to avoid fast lvl 50 reach.
Thanks for the answers to come.