Pros: Cool style, 360 degree speaker rotation, great open sound, cord length and thickness.
Cons: Lots of sound leakage: not good for office or travel.
So, I'm an audiophile noob, relatively speaking. I bought these about three years ago for $180 (I'm Canadian so everything good costs more for some reason even though our dollar is higher than US right now). These were my first good pair of headphones approaching audiophile status and they changed how I listen to music forever. Since I bought them, I've been on a never-ending mission to convert as much of my music library to FLAC and apple lossless because I had no idea what depth and detail there can be in music played on headphones until I bought these.
Maybe I don't have as good an ear as others claim to, but based on my non-professional opinion:
Lows: not too much emphasis on bass which I find can be overwhelming with some HP's at the expense of other frequency ranges. The bass is great though. Very punchy and it hits the very lows well with no distortion. I haven't been able to cause distortion in these yet.
Mids: Well, clear I guess.
Highs: I feel as though the highs are emphasized a little more than lows and mids, but they're still clear and great.
Overall: I love the headphones. They introduced me to the way music should be heard by everyone. And now all I want is more headphones. I'd love to get another Grado model, but I also want to explore other types of headphones. I can say that I've tried several pairs of Monster beats (I know that they're different because they're closed back but...) and none even come close to the audio quality of Grados. I fell sorry for people who spend their money on beats just because they look cool or something.
After buying these, I went for a pair of Monster Turbine in-ears, that I like but are a totally different thing than the Grados, and obviouisly not as good, but still quite nice for small and portable. I also have a pair of white Audio Technica m50's on the way, and I'm looking forward to comparing them to the Grado SR80 soon.