Why are you waiting to hear what the drifter says, The warning is when your screen turns red !!! The Invader isnt exactly hard to spot n fact they are easier to spot than the opposing team sometimes as they are bright red. Personally i like the fact that you have a target on your back when invaders come over it makes you more aware and adds a sense of excitement to the game. If you take away the Icons then simple fact is nobody would invade as it would pointless because you only have 30 seconds and it would take that to locate the opposing team.