I think one of the strongest selling points for these phones are their comfort. You don't think you need it until you try it once and understand the difference - because it turns out being distracted by any discomfort will disrupt your listening experience in ways you really wish it didn't. These headphones feel incapable of discomfort even if you wore them all day long.As for the sound quality, these phones (like any other headphones) are going to show 'colorization' at certain frequencies and this model has colorization behavior that concerned me and most likely others too.These headphones are a just a bit too bright at louder volumes (particularly for music). It's very clear they are this way if you check out their frequency response graph (see photo) - especially at higher volumes. Another graph clearly shows it gets even more pronounced the louder it gets (see photo). If you don't suspect you will listen to these at louder volumes most of the time, then this isn't really an issue, and can actually be an advantage because brightness at lower volumes generally improves clarity.That said, my impression is that these headphones were not quite intended to be used at higher volumes. From a numbers perspective, the graphs show this, and additionally, this particular model is rated up to 100 mW of power whereas other comparable phones can handle up to 1,000 mW (there's not a lot of room for loud volumes / higher power use). In fact, if you run these at louder volumes, you can tell they start to clip a bit sooner than you might expect.Granted, a lot of people are not going to use these at higher volumes - but I also know there are people out there that really want to listen to music loudly (not ear bleeding!) and these headphones show concerns at the kind of loudness I am trying to describe.If you think you will listen to these loudly - what you can do about it is use software (or hardware) to alter the EQ of whatever you are running these on. I use them on my laptop (behind a DAC/Amp) and for those of you who are using them on a computer, you may be very interested in a free software called Equalizer APO along with the Peace plugin. It will give you a 13 band EQ where you can set the changes wherever and however you want. The most useful feature of this software is you can overlay the picture of the frequency response graph on top of the graph of the changes you are making. When done this way, you can achieve a highly accurate and complete correction of the colorization (see photo). Do note that if you do this, to not apply as much correction as you get closer to the high end because of the way the headphones behave with volume changes - you will want to only correct about 2/3 to 1/2 as much to give some room for these changes.If you bother to do this - it will drastically improve the sound profile of these headphones. It will feel like you added 100's of dollars of value to them because frankly - it's quite difficult to manufacture headphones to sound uncolored by themselves - the physics behind it will always introduce some colorized sound. There is some color you may want and others you don't - but if you don't bother to use something to correct for the colorization - you might find yourself wondering if some other pair of headphones will more closely produce your 'ideal' sound and begin a cycle of trying to find that 'perfect' pair and keep discovering they all have some bit of colorization.If you spend about $150 here you can get top of the line comfort and very capable headphones, and for free, help correct it's sound profile to your needs.Now, you can't improve certain things like sound stage or imaging this way - but if you were concerned about that there's a good chance this model wasn't your first choice because these are closed headphones and not the top of the line model offered by this company.Beyond the brightness colorization, the mid and bass response are great. The mids stay pretty neutral at all volumes. As some people have noted, they can be bassy.Yes - they are very capable of reproducing the low end in ways most headphones just can't. To be more specific, they have pretty good low end *range* - as in you can really hear the sub bass. But, there is a slight problem with their bass response at specifically around 210 Hz.I highly suspect with non-electronic music you may not notice this because it's not the most represented frequency - but if you do listen to electronic music - there's a good chance you will feel the bass doesn't quite sound the way you remember. Well, it happens to be a prominent frequency for kicks and bass lines - so it's fairly present in the sound spectrum for electronic music. I would boost this area specifically to see the difference and leave it at that.There will be some people who think that, overall, the bass is too present, and indeed it's true that there is significant bass response if you look at the frequency response graph. Just like with the brightness, it gets more pronounced the louder you go. For those of you who listen to electronic music, there's a good chance you will really appreciate this - it can be amazing how these headphones respond. However, if you don't listen to electronic music - this is probably unwanted in a lot of cases. Again, I would apply EQ correction for this - but in this case I would just apply an overall bass reduction as the bass response is pretty even unlike the high end which has several peaks and valleys in that range and is more complex to correct.That about wraps out my thoughts on the sound quality.I will say that if you don't have an amp for the 80+ ohm models, you will most likely find these too quiet - they will sound about half as loud as you expect they can achieve. This is expected because of the higher resistance. Most likely, you will want an amp to drive these. That said, I don't recommend the 80+ ohm models for mobile users... those are more for stationary users.If you don't already have an amp, and plan on getting one, do yourself a favor, and make sure that either your amp has a built-in DAC, or plan to get a separate DAC. The main reason for that is the DAC will ensure the amp is getting the kind of electrical signal it's expecting. In my case when I only had the amp and no DAC, the amp was prematurely clipping at lower volumes because of the output from the laptop - this was immediately fixed by the DAC I bought.As for the build quality - pretty sure these will last a lifetime with care. There's nothing particular cheaply made that I noticed about these phones. I'm not concerned with the way they look. They aren't displeasing to me - but I'm also not thinking these are the coolest looking phones, but I don't care about that.