One remarkable thing about their sound is how they capture the sense of hall space in acoustic recordings. In one recording of the Bach St. Matthew Passion, for example, I could actually hear the tenor voice of the "evangelist," who was positioned on the left of the stereo panorama, reflected from behind my head (honestly!) off a right rear wall. Most headphones seem incapable of playing back this kind of detail which is too bad because that's what's responsible for most of the spine-tingling realism in the playback of a recording. The iGrados give you that at a reasonable price along with a smooth, realistic, dense, articulate, full-spectrum sound that isn't "pushed" in either the top or bottom ends.
Pros: The iGrados are worth a try if you truly put a premium on quality sound. The iGrados can be used during exercise and will stay securely on your head, I suspect, even when bungie jumping. Unlike many with an 1/8" plug, they sound more like high-end audiophile headphones.
Cons: The spiring-loaded, behind-the-head design does put a serious squeeze on the ears and head, but nothing I couldn't get used to. I seem to have suffered no impairments or loss of... loss of... I can't quite recall the right word... but after two weeks of using iGrados I can take a hat one half size smaller. Apart from their vice-grip feel, iGrados don't give the impression of being particularly moisture resistant, so I expect to go though more than one pair of these in my lifetime.