Every exotic is rare, just because you've seen it drop means nothing. I've never seen Suros drop or have never gotten it but someone else may have seen it drop a few times. If you were to look up the number of gjallarhorn owners compared to non owners it would be pretty lopsided. You see a group of competitive players in a raid with gjallarhorns doesn't mean it isn't rare. You go to a race track your gonna see some Ferraris