You know how Grados are forward, and Senns are laid back? Alright, those were easy to characterize.

Beyers and AKGs and Audio Technicas are a little harder to characterize, because they're in between. They're all pretty straightforward -- not too forward, not too laid back.

The Beyers are probably a little closer to the Senns than the Grados, but I wouldn't call them "laid back". They're just sort of "there". They have this really pleasing straightforward balanced tonal spread with nice extension (I'm specifically talking about the DT880's here). That's what I like about both them and AKGs (like the K240...M? I think...maybe the S...I forget...).

I usually listen to the DT770's, which are even more laid back than the DT880's, and not as neutrally balanced in the frequency spectrum -- they are definitely basshead headphones -- but they also go lower than most any other headphone. Although I've been listening to my DT831 lately, and that's pretty close to the DT880 (sort of a poor man's DT880), IIRC.

As to K701 vs. DT880 -- hard to say, I currently own neither. I had a chance to A/B the two (actually A/B/C those two and a pair of rewired HD650's, all balanced) on a really high end amp, and they ended up sounding very similar, tonal-balance wise. The difference was in their ... I'm not sure, it almost sounded like phase issues -- the DT880 just cleaned up the other two in this area. It just had a cleanliness to the sound to it that the other two didn't even come close to. (The amp in question was Headroom's Max Balanced with the new diamond buffers -- the best solid-state headphone amp I've heard, and one of the best headphone amps I've heard of any topology. To use bartender's terms: "top shelf".) There was also a slight "weight" that was missing in the AKG, though I still like it more than most of my friends do...it was a little "drier" than the Beyer (but not HP1000 dry, which is dry like a martini dry).

Let's put it this way -- I'm in no rush to get the AKG K701 -- I will probably get one some day, but the DT880 is a little more imminent.

Gee, sure typed a lot, hope I said something worthwhile in all of there. Feel free to ask more questions to drive my answers in a specific direction...