Summary:
The Koss R/200s are the best sounding sub-$100 headphones that I have listened to. They are solid thoughout the sound spectrum with perhaps a little weakness on the subsonic end (

Strengths:
Accuracy, detail, clarity, price.

Weaknesses:
3d expansion box, comfort for extended sessions

Similar Products Used:
Sennheiser: 500, 570, Kenwood KPM-610 (?), variety of Sonys, JVCs