After getting over my worries about spending so much on a pair of earphones, I took the plunge and bought a pair of ER4s. I'm so glad I did, they're worth every penny. I previously had a pair of ER6s, and while I was really happy with the sound isolation and sound quality, the puny cables left a lot to be desired. Thankfully, the cheap build quality that ruined the ER6s is gone on the more expenisve ER4 model - the cable feels robust, with a thick, durable coating. The ER4s are confortable - once you overcome the initial shock of being able to hear your own heartbeat while wearing them - and the sound quality is like nothing else. I briefly owned a pair of Bose triport in-earphones, but took them back because they were awful. I can't recommend these phones highly enough to anyone with a love of rich, detailed music from their portable device. You'll need a few quid to get them, but like I said previously, they are more than worth it.