Well, my friend has beats studio 1.0's, and to be completely honest, they aren't good. The treble was grainy, the bass was too loose and muddy, and vocals were scratchy... Now, beats studio 2.0's are another story. Those are pretty good imo. The treble is listenable, bass is tighter, and vocals are finally good! Of course, I own an 80$ headphone that they can't quite beat in sound quality, but hey! Its good to see Dr Dre actually handing out decent cans that at least mostly live up to its studio name! Haven't tried pros, and solos?... Ugh. I wanted to stomp upon their soulless diaphragms. They are absolutely hideous sounding for 200$.
Now, their mainstream competitor made by the company that was betrayed, monster with the n-tunes are awesome little things. I love their sound. Its bassy but clean. Not Terribly muddy and bassy, but some oomph to the lower end... All in all, beats by Dre are decent sounding, but not for 300$. The looks and comfort, plus amplifier at least mostly make up for where they falter. I'd like to own a pair actually, but I'm not rich enough to buy that without regretting it and wishing I had bought an Akg, hifiman, or other audiophile brand.