I bought a pair of these for my father on a whim after looking at Tyll's measurements and reading about some of the features on amazon. I accidentally shipped them to my own address, so I decided to put them through a few paces while the post office takes their holiday. I just sold my last pair of dynamic headphones, so it felt ironic enough to go with it. Hopefully my dad won't mind.
I haven't listened to them much, but from a accessories perspective I like what they're trying to do. Dual-entry, detachable cables really should be the standard given today's headphone market (whether you believe in cables, or you just need longer/ differently terminated ones). That being said, their non-remote cable could stand to be a bit longer. Carrying case is a nice touch- I'm not used to a company covering all the use cases from office to home and everything in-between, but that might partly be due to my being out of the sub-500 market for a few years now.
While the accessories are very thorough, the build quality doesn't quite live up to the same bar from what I can tell. The locking mechanism for fit adjustment seems to be susceptible to manufacturing variations; the right cup seems to want to retract on its own randomly. It happens consistently, so I assume the spring that is inside the headband is loose or something to this effect. Luckily this is less of an issue given the clamping force of the entire assembly, but at this price point I would expect more. $300 is a lot to expect (non-audiophile) consumers to pay, and these little hiccups don't really fly when you consider that at this price point people could be buying beats or whatever musician-backed headphone is making the rounds these days. Clamping force could be a bit high for some people as well, but I've been conditioned by the Audeze and Stax offerings so I'm pretty sure the nerves around my temples and ears have been desensitized. The headband doesn't seem to apply pressure at the contact point, but I worry about the longevity of the foam inside. The earcups are a bit on the small side, but they enclose my ears without much discomfort. The earpad material is also fairly nice. but I think they were made firm enough so as not to compromise the clamping/sealing properties. From a purely comfort-oriented perspective they could stand to be a bit softer; ultimately I can see the fit being a make-or-break at the end of the day for a lot of normal consumers. For what it's worth I consider the D2000 and HD800 more comfortable than these. Of course the benefit from this kind of fit is the superior isolation, but I can't comment on how good this is as I've only used open headphones for the past 5 years or so.
I'm doting on the non-sound related features because I think the market that NAD is targeting isn't focused on sound quality, and I'm pretty sure my father also falls into that demographic. That being said, these are quite good for what I have paid. Extension into low frequency bands is good for what I consider to be small drivers (40 mm). I haven't actually read Tyll's review or done proper research (pure impulse gift), but from what I can tell NAD is trying to scale back a bit on the treble intensity and tune the bass for a little more kick/reverb. I think for the most part they've succeeded but it creates some strange banding between the low/mid/high frequencies that I start to notice on pop tracks. The vocals will clump into the middle, and the bass gets pushed outward. While this collapses the soundstage a bit, I'm still impressed by the separation - it just comes off as a bit unnatural. I like that they attempted to tone down the treble response, a lot of dynamic headphones suffer from over-energized high frequencies. I used to equate this with "neutral" and "analytical" sound, but after doing this long enough (at the expense of some of my hearing), it just ends up being really fatiguing. Again there is a bit of frequency banding so cymbals and similar sounds will tend to "pop" out, but I think at this point it might just be a preferential thing. I would consider this an intimate headphone when considering all of the above- there's not much in the way of "airiness" and the emphasis seems to reside in the mids. I still think they've managed to do some pretty interesting things with the presentation despite the shortcomings. It's very easy to relax and enjoy the music, but if you start picking apart details in your source material everything is clearly delineated.
All in all I'd have to agree with the title of Tyll's article (because that's all I've read)- it's certainly competent. I think that for the price you're getting a lot in terms of the sound, and the case + cable extras are a nice touch. That being said I'm let down a bit by the build quality- obviously I know nothing about the supply chain logistics or the profit margins they are netting, but I think most consumers are paying for the comfort+build first and foremost. Issues with something as basic as headband locking are pretty inexcusable. I will give them a nod to aesthetic design though, I don't look like a total clown when I'm wearing these. I should probably grab a pair for when I'm out on the go, clearly my K1000s aren't cutting it. My bottom line: I think my dad will like the sound and isolation but experience some issues with the fit and polish.
I wrote this in the span of one album, and I don't really plan on giving these the time I know they deserve. However, I hope my impressions help any prospective buyers out there. I guess I should also add that I've been horribly spoiled by the 007 mk1, so my measuring stick might be a bit skewed.