Pros: Really musical headphones
Cons: Comfort, fatiguing, congested
I owned these a long time ago so this brief review is written from memory.
The Grado SR80i may be the best rock headphone for the price. The in your face presentation of the sound, the sharp mids and highs and tight bass really brings the listener into the music. The problem is they may be too in your face. They feel as if sound is being injected into your ears while the mids and highs that were once fun are now very bright and causing fatigue. Comfort was an issue for me as well, I had a hard time wearing these for 2+ hours.
I said they were possibly the best rock headphone for the price, but outside of rock music I found these lacking very much. These are rather one dimensional headphones.
I think the Grado SR80i are a fantastic headphone, but I think many users will love/hate them as I did.