I used to play Battlefield 2 Project Reality Mod; pretty much similar to ARMA, Squad and Insurgency. Limited to no HUD, no friendly/enemy trackers, no ammo count (just clip count), 64 player servers. It was amazing; communication was top notch; love the callouts for bearings/azimuth, suppress firing, unknown targets, movement of squad makes you feel powerful but fragile.

I might pick Squad up to get myself going again in realistic FPS. RM75 is pretty decent. How many players and maps are we talking about in Squad?