I think that the stalker mode sounds good, and something about the holdout mode, I think the defenders should be given match points like in LFD2, so they take the longest they held out for, and give the team a few points for every 10 seconds they hold the objective, a major bonus if they survive for the whole match, and a multiplier for every person still alive, an ambush mode could also be interesting, as in team A are elite soldiers, but no re spawns, and have to work as a team to get to the exit, whereas team B are grunts, but unlimited and have to stop them, like LFD, but with enemy soldiers. I love maps with a vertical element and would love to see this in at least one map. I think stalkers should be quite acrobatic and be able to free run about the place to avoid fire or get to a good vantage point. I certainly like the idea and I like the idea of the different styles of weaponry for each faction.