These headphones have the perfect sound signature IMO. Mostly Neutral with some emphasis in the right places to liven up the sound (in the mid bass). Compared to my Sennheiser HD600s, the NAD Viso HP50 I think are better sounding for all subgenres of electronic music, hip-hop, and metal. The bass is punchier and has better extension. And the HP50's are closed, which makes them way more useful than open headphones for me. It comes with a nice zippered carrying bag and lots of accesories like 2 diffent cables, one with and one without a microphone.

Their are a few downsides though.

• The ear cups are small and so they can be uncomfortable unless you have small ears. If you have ears like Barack Obama, you're gonna have problems. There are some mods you can do to alleviate this (by adding foam weather stripping underneath the pads), but be careful to not damage the serial number if you have the warranty available.
• The 'creak' from plastic-on-plastic friction in the ear cups. You can again alleviate this with mods (lubricating the hinge adding felt etc. to the inside where it rubs against the housing). This is a much bigger problem on the early version of the headphone compared to the other
• The pleather on the ear pads almost immediately starts flaking off (see attached picture). This is mostly aesthetic since underneath the pleather is just a weaved textile material.
• They aren't very durable. The cable that connects left and right drivers can inexplicably break. This happened on the early version of the headphone so maybe they fixed it.
• The early version looks especially goofy with its more 'square' headband (see picture)

These were the best audiophile purchase I have made. I've used them nearly everyday for 5 years, and I have little desire to purchase another set of open over-ear cans.
 
Sound:
The sound signature is neutral. Some have criticized the treble for being rolled off. While the treble lacks a certain energy (stemming from a lower quantity) one might find on Grados, I find that it still replicates high frequency instruments very well, and that the "laid back" nature makes listening non-fatiguing. They also have a great airy sound to them, which makes them sound more like speakers (which is a good thing).
 
The bass response is perfect, not too little, not too much. They can "slam" as much as the music allows. Using a decent amp helps in this area. In my experience, I can not tell the difference between my cmoy, Aria Headfive, EMU 0404 usb headphone out, and from my Onkyo receiver headphone out. These are all considered to have/be good headphone amps. You don't need anything super expensive.
 
The mids are very rich and full. It's got just the perfect amount of warmth in the mids.
 
Comfort:
The padding is velour, and is extremely comfortable.
I have longish hair, and sometimes the headband pulls  on or rips out my hair. Once you know how it happens, it's not hard to avoid.
 
Conclusion:
I just don't see how anyone could be disappointed with these. They just do so many things right. They also aren't that expensive nowadays.

Audio Quality: 1/10
 
These sound much worse than my cheap Sennheiser cx300s. They manage to suck all life and energy out of any track I listen to. I actually enjoy an analytical and neutral sound signature. These however don't have the detail or sparkle to make up for it's lame frequency response. They just sound thin, small, and dull. There is no fun to be had in the low end. It's there, but it will not make you bob your head or shake your tail feather. With super cheap IEMs, you at least usually get some silly fun bass for amusement. Sadly, these IEMs will just make you enjoy your music less.
 
The mids are the focus of these IEMs, and unfortunately, they also suck. Congested, boring, edgeless.
 
The highs are a joke. I thought the Ety sound was all about the treble?
These headphones have magical treble: they can make entire instruments, disappear! Where once there was a high hat, there no longer is! TA DAH! My Senn cx300s sound like $300 IEMs in comparison.
 
I don't really even understand how this happened. Its as if all frequencies are recessed, but turning up the volume solves nothing.
 
And obviously there is no sound stage, its an IEM you dummy.
 
Comfort: 6/10
 
I'm being nice, since I actually found these to be very hard to fit with the stock tips. But this is partially because my ears are jerks and are shaped stupid. I fixed this with some after market foam tips.
 
Isolation: 8/10
 
Great isolation, I can't hear crap!
To bad I'd rather listen to the outside environment than these pieces of crap.
 
Design: 9/10
 
Built extremely well. The cord is kevlar reinforced, which will come in handy when you try to hang yourself after listening to these crap IEMs.
 
Value: Whatever, don't buy these. Save your money, they suck. Others won't come out and say it as bluntly, but this is clearly the case.
 
I wish I'd bought 2 pairs of cx300s instead of these.

These have a very thin and dull sound. There is a noticeable lack of low mids / bass, which leave the headphones sounding very cold. There is no sound stage to speak of. I just can't find any redeeming qualities in the sound department. My cheap Senn IEMs sound much fuller than these.
They do isolate extremely well, at the expense of strong head clamping and ear warmth.
 
Stay away from these. Frankly I'm astonished that these have 4 stars (as of this review) on a site dedicated to headphones. I suspect people want to believe their $80 were well spent.