I've had the Share E3c for over a year and use them 2-3 hrs a day on my train commutes as well as 5-10 hours on trans-Pacific flights (w/ iPod and watching videos on Powerbook). No complaints or problems with them.

My son has the Etymiotic ER-6 - which if I had to purchase a replacement, would personally prefer over the Shure. Better seal (not really noise cancellation per se), better bass.

Both around $100....

However earphones are very personal and you should try them out before making final decision.

PS - failed to mentioned bought second pair for friend in HK; he had problem, shipped back to me to return to Shure, who provided free replacement. So second those who advise Shure provides good service. Also, you should be able to buy this model for around $100 via eBay - it's been around quite a while and price could be actually under $100 by now.