Nothing against the headphone itself, but the HD650. Pretty reasonable headphone, a bit overpriced which hurts it. It's the crowd that follows them that drives me crazy. I have zero interest in the phones, but I've heard them quite a few times. The first time I had all of 10 hours to try over $50 000 of headphones. Since then my opinion of them has not changed. Amazing 'relaxing drink in a dark room' headphones, but I would not want them near daylight. I'd love to own a pair though, if someone would buy me one.
The crow that follows them is probably the worst. Perhaps it's only 1 or 2 people that ruin their reputation for me, but it matters nonetheless.
The M50 I feel deserves its spot. $100 for a slightly bassy, relatively neutral closed headphone? There is nothing else. The shures were more expensive and boring, which does not suit the crowd that is looking for the m50s.
Underrated, RE1. As much as the head-direct/hifiman comany is questionable, I think this is one hidden gem that I would still enjoy from day 1, even though I don't really feel a burning desire for them. The triple fi 10 were also surprisingly nice for their price, which shows how big of a role expectations play on our experiences (there's a detailed study somewhere, which is why I dislike headfi so much; I am reminded of this perpetually). I was expecting it to be 'meh', but the U signature was extremely enjoyable.