Pros: Excellent bass and mids, clear highs
Cons: Reveal bad quality mp3 recordings
Disclaimer: Rather than being an audiophile like most of the members here, I consider myself to be just an enthusiast consumer. I have very limited experience with headphones and anyone looking at my current review should be aware of that.
The PAA-1's are my first decent earphones. Despite being entry-level if judged by price and appearance alone, the sound they produce is good and versatile compared to the bass-heavy iBeats by Dre. Good bass and plausible mids with a bit crippled highs form a not at all bad sound signature, though I imagine other high-end buds would, of course, surpass those.
A somewhat important fact is that the buds are on the bigger side, therefore if you have small ears they might fall off or just cause discomfort or even pain in the earlobes.