My experience with invis hunters usually goes like this. Hear a hunter go invis and know exactly where they are coming from based on the sound while they have reduced radar, see invis hunter come from the logical lane in the direction I heard the sound, kill invisible hunter, profit. Invis loses a lot of its value when used against players with good map knowledge, since there just aren't that many lanes to use. And when I do die to one it's not because they are invis it's because I was outnumbered.