First post here...
I've had the HP 50 for about a year now as portable headphones and mostly used them in combination with a HTC One or a Laptop. As they are my first pair of non-headset over-ear headphones, I can't contribute any comparisons, but I've been generally happy with them.
Admittedly, I never compared them to anything else, neither before nor after buying them. They seemed to be a good choice in the Momentum price range (as I got them for slightly less than a pair of Momentum's would've cost). My early issues were the relatively poor isolation compared to the usual in-ear headphones I had been using previously as well as the ergonomics. I have rather large ears... The latter got better over time (got used to the fit of the headphones), while the former was only relevant in really noisy environments (busy street, badly isolated train wagon...).
There is one construction issue (at least with my pair and/or my way to use/transport them), which is the hinge holding the earcup. It seems to be an aluminium part which is attached to the plastic part from the earcup by two miniscule screws. Somehow, one of those screws has managed to unscrew itself several times now. So, if any of you hear a rattling noise from the earcup, I suggest to check those screws .
Unfortunately, my pair broke yesterday. >.< I have never been overly careful with them nor have I been overly rude. They were always transported in a backpack, but they dropped 2-3 times from about desk height. This didn't do any harm until I managed to drop them once more yesterday - again, from the desk. Afterwards I noticed that the spring, which rotates the right earcup back when you twist it, didn't work anymore. When I inspected the damage more closely today, I found that the hinge at the end of the extendable wire of the headband had snapped (it's a metal part... o.O). I'm now able to pull the earpad from the headphone.
They still work perfectly and the earcup holds because it fits tightly enough into the hinge. But I'm not quiet comfortable with this kind of mechanical damage. Without replacement parts, there isn't much hope of repairing them I fear. Glue might not help much or for long in this case. Any suggestions or experience? I'd really like to repair them or have them repaired...
This is what it look like:
https://flic.kr/p/prY1fA