First post on this thread. These headphones weren't initially on my radar at all, but recently had the opportunity to have an extended session with them at a friend's place. Powered by this ORB dac/amp unit - not a company I'm familiar with so not sure what the model name/number is - the R70x sounded really, really good. A lot better than I though it'd sound, for sure.
They seem to be the kind of headphones that don't appear to have any standout quality whatsoever, but somehow just end up being extremely relaxing for long listening sessions, even with more energetic music like electronic stuff. They also seem to be very forgiving of track quality, (even 320kbps mp3 podcasts/streams sounded quite decent), although they did scale up well with the higher bitrate stuff I tested as well. Not the type of headphone that'll wow you like a Fostex TH-XX/600/900 will with bass slam or like Audio Technica's own wood models with vocal presentation, but the R70x is just so unfatiguing in the long run that you don't seem to ever want to remove them. Not sure if any of these properties would be good for a mixing/monitoring/producing type headphone (I always figured you'd want ruthless and up-front sounding cans for that), but for a pleb enthusiast like me, they're golden.
Soundstage isn't the widest I've heard for headphones in this price range, but the imaging within the soundstage felt pretty accurate, for the most part. I read some articles and forum posts mentioning they were a bit light on bass, but to my ears, paired with that ORB unit, they conveyed just enough low-end heft. Obviously not DJ-headphone kind of bass slam, but not anemic by any means, even for tunes that have most of their meat down in the low frequencies. Ultra-low frequency (sub bass) content is another matter altogether, and this is one area I feel they don't quite measure up to some of the best headphones I've tried/owned, but most of those headphones are double the price of this, some even more. Another negative I detected was some graininess in the upper mid frequencies, though that didn't surface itself on every track I tested, so may well be an issue with the actual tracks and not the headphones. Would need more time with them to form a concrete opinion in that department.
Oh, they're also supremely comfortable. Not the most robust feeling kit in the world, but they're so light and the pads are so airy. I don't think I'd need to switch pads for my ear size, and those floating wingamajigs conform to my skull pretty well, way better than some of the audiophile-woodie Audio Technica models I've auditioned in the past, if memory serves. Cable is way too long for my liking though - great for listening on the couch or while walking around your studio or whatever, but for regular "desktop" listening, it's way more than what I need. Seeing how you get shorter and coiled cable variants in the box with some of Audio Technica's cheaper M series models, this seems a little skint for them.
Either way, definitely a headphone that's on my radar now.