I just got these delivered today after waiting patiently for 2 weeks. First of all these are some sexy looking cans... Secondly, these are truly an enjoyable listen. Coming from the 990 DT’s, these are pretty refreshing. They’re also very very comfortable, but I am aware that the pads wear out after about a year so I’ll have to grab another pair. But overall, probably the best $350 I’ve ever spent.
HD6XX and other 600-series headphones are some of the easiest to recommend because they make for such a good reference and are so easy to listen to. I wouldn't say that 6XX performs impressively with everything, but for listening vocals and acoustic instruments, they are wonderful.