Yes, I have had these and used them for a few months now as a work headphone and I have to agree that they are VERY relaxing to listen to. Everything just sounds natural and spectacular with them. They are easy to listen to. I wouldnt say they do everything right, but they do exactly nothing wrong. I use these for work 9 hours a day at work and non-fatiguing is the least that I can say about them, which means they are soooooo goooood. They just make me want to kick back In a Lazyboy and kick back with them on. Pads are a bit small though. the AD900x pads fit much better, although I cant switch back and forth fast enough to really dial in on whether or not there's any sound difference. AD900x pads fit very loosely on them, but I could see someone making it work.
I wouldnt say they are technically superior to the HD600, I own both, and its not a popular opinion on this forum, but I have to say that separation, imaging, and background blackness are better on the HD600s. So bottom line, HD600 is better in ability and technicality, but the R70x's are better for when you want to ENJOY the music at its fullest enjoyment potential, with just enough detail so it doesn't overly analyze and criticize the music.