Excerpt: I primarily purchased these phones to experience great sound while exercising. They have great overall sound. A bit wimpy on the bass, but vocals and instrumentals come out crisp while still remaining warm. Very easy to listen to. The different ear adaptors are all pretty comfortable, and the 'default' ones have no trouble staying in while running. One complaint is that they isolate the environment so much it become difficult to hear if something important is happening.
Excerpt: I use these headphones everyday on the train and they are exactly what I was looking for. The sound is very clean, the cleanest I have heard from headphones. They provide excellent noise isolation, almost too good. I use these everyday and they seem durable up through now. The included case is nice too when it's time to stash them and get to work.
Summary: Got these as a replacement for my broken ER6i's and are great so far. I use the foam ear tips and they are great for noise isolation and sound. No complaints at all. I had previously purchased the Bose noise cancelling in ear, ear phones and thought they were pretty poor. The MC5 suits me much better.
Summary: I never liked the ear plugs that go right into the ear before now. My husband bought me these as a gift and I have not had any issues with them falling out which I always had before. They cut out a lot (okay all) of the surround noise which is brilliant in the gym.