Pros: Dead neutral, detailed and revealing (though oddly enough, not on the same level as the much warmer HD-650s), extremely comfortable (for me anyhow)
Cons: Not "fun" to listen to. Cold, analytical and soulless poorly amped, hardly inviting even out of my best gear. Cheap plastic on band breaks easily.
And yet, of every headphone I've ever owned, heard, lived with, worked with...you name it at a sane price range, these are the ones that time and time and again I come back to when I'm testing out new gear. That should basically say it all. When I want to know what, on average, a new DAC or amp (especially a new amp) is worth, these are the first cans I run through them. Because if it can do these justice, it's looking good for pretty much every other hard-to-drive can in my inventory (and there are a few). I also use these pretty much exclusively for tracking and mobile editing.
And as much as I want to malign their lack of apparent musicality, I nevertheless end up using them for my own personal listening pleasure more often then I'd like to admit (which may just have something to do with my being used to how they sound, but we'll leave that aside for the moment). I'm the kind of person who likes neutrality, detail retrieval and subtlety. Given that I lack a solid tube HPA at the moment, it may well be there that there is warmth and musicality lurking in these yet, but given that, on average, my choice for high-end listening is usually between these and HD-650s, I usually end up choosing these because at the end of the day I feel like I'm being hoodwinked, bamboozled by the Senns. So many of the tracks I know and love I've heard as studio masters running through studio monitors. I know what they were, for all intents and purposes "supposed" to sound like. And, with that context, they never sound the way they "should" for me quite like they do with K702s. For 200 bucks street, all other qualms aside, that's a mighty huge achievement.