Amazing Headphone!  I got this from a deal which only costed me $60 including shipping.  What a steal!
 
Intro:
I'm a uni student and is very interested in audio and headphones.  I currently own the ATH-M50 and the Focal Spirit One which both I enjoy a lot.  However, in receiving my HPH-200, I found myself picking up less of my other two headphones.
 
Build Quality:
The build of the HPH-200 is not bad at all, however it is not as nice to look at as the M50 or the Spirit Ones.  The construction is rigid and doesn't seem to make any cracking noise as i stretch the headband which I sometimes can find on my M50s.
 
Comfort:
This headphone is very comfortable, light on the ears and the velour pad have some nice soft padding.  The velour pad can get itchy at first, but I found myself quickly adapting to it and does not feel a thing now after 2 weeks of use.
 
Sound Quality:
I pair the HPH-200 with my AUNE T1 DAC/Amp and play flac, wav or ape from the mac pro.  I love to listen to jazz and i think in my opinion the HPH-200 is very capable in this area and much more enjoyable than the M50 and Spirit One.
 
Bass:
HPH-200 got some very good bass, well extended, goes very deep and has a nice powerful thump to it which I have not heard before.  It is not muddy at all and does not get in the way of the mids and vocals.
 
Mids:
The vocal sounded a bit far away at first when the headphone was not burnt in.  One thing to note is that these headphones really needs to burn it as I found dramatic changes.  At first the mid sounded very cold and does not make the vocal appear.  However after about a week of listening, the vocal really shines and, but I still think it is not forward sounding as is the M50.  Also, I found listening in complete isolation makes a lot of difference and I was able to listen to a lot of small details in tracks.
 
Highs:
One thing I can say is that it is not fatiguing unlike the M50.
 
Sound Stage:
Wow!  The sound stage is phenomenal!  It has a very wide sound stage, instruments are separated very clearly.  The depth is there but to me was not the wow factor.  Lastly, the height, i didn't even know it could exist in headphones. 
 
Overall:
I am not an audiophile, but I reviewed this completely in my honest opinion.  For the money, this headphone is unbeatable!  For anyone who wants to try out open air headphones, but does not want to pay the premium price, this headphone is the way to go! 10/10! 

The ATH-m50 is my first ever headphone, not including the $2 ear-buds of course.  Before the m50, I was just listening to ear-buds and didn't have much affection for music reproduction.  However, this has changed once I had the m50 in March 2014, which made my wallet quite unhappy as I made several other purchases such as the AUNE T1 DAC/AMP and the Focal Spirit One.
 
Comfort:
I think the m50's overall comfort is not bad, especially compared to my Focal spirit One.  You do feel the clamping force on your head as soon as you put it on and it does not disappear even after six months of use.  The clamping force didn't annoy me much, but when I listen to it for long session, I had to take them off every hour or so as the ear-pads were too sweaty and uncomfortable.  Another reason for this, is that the pleather ear pads are not very soft and changing it to the velour ear pads may be better.
 
Build Quality:
The m50 is build like a tank although it is full of plastic.  I do take a lot of care for my headphones, but after six months of use, there are still no dents or scratches that I can find!
 
Sound:
The bass is definitely emphasized which can be good or bad depending on the genres you are listening to, although emphasized, it is not bothering and is very enjoyable.  The treble is sometimes fatiguing as it reaches the higher notes, which is quite disappointing for me as I found the spirit one to be much better for my taste and music.  Soundstage is better than the Spirit one, and good for a closed back.  The soundstage is not mind blowing, but it does give a good overall presentation of where the music are coming from.  I THINK they do burn in, as I found the bass to be much tighter after a few months use, however it may just be more perception.
 
Conclusion:
The m50 is definitely a good entry to Hi-Fi although it is not a Hi-Fi headphone, it gave me an enormous difference in listening to music.  I can be sure of one thing, once you listen to the m50, you can never ever go back to your $2 ear-buds again!