Pros: Clarity, detail, tonality, driver speed
Cons: Slightly thin presentation, stupid AKG headband
It's like listening to music with an electron microscope.
If you're looking for recording flaws in your music, by all means pick these up, they have no modestly in pointing out every single one. But for pleasure? Forget about it. Simply put, these headphones are too hot in the treble. If you want more nonses tacked on to the end of that sentence please read some other review.
Soundstage: Imaging is certainly more sophisticated sophisted than the srh840, but it's really only noticeable on classical or live recordings. Still, the effect is not to be understated. It really does add to the effect if your music collection flls under that umbrella.
Design: Shure really knocked it out of the park designing something even doofier looking than the 840. But I think somewhere along the line they realized they had no idea what they're doing and threw in an awesome carrying case and an extra cable and set of earpads to make up for it, so I really can't be too mean about it.
Comfort: Much improved over the 840. Instead of the pleather sweat traps you get soft velour which stays very cool and dry. And instead of having to wear a piece of rubber on the crown of your head you get... a K701 crown-of-thorns style headband. So while I guess Shure still doesn't really understand the whole comfort thing you do get the lesser of two evils here. They also clamp a little harder and aren't as top heavy, so they stay on your head better even if you're a headbanger.
Some half assed photography:
edit: I've gotten rid of these, over time their very revealing and slightly thin character didn't sit well with me. Stunning midrange though, if I get another headphone that at least equals it I'll be very happy.
I've also knocked down the value rating, these are certainly detailed and smooth sounding headphones (despite their treble) but these weren't enjoyable in enough genres for me to justify the asking price.