Sennheiser CX 300 Consumer Headphones

I purchased the Sennheiser CX 300 ear buds as replacements for the stock Apple ear buds that came with my iPod. The sound quality is considerably better, especially the bass. They do block out ambient noise well.
I don't like the fact that the different ear cords are asymmetrical, and that the cords transfer noise when brushed against clothing. But the big problem I had with these ear buds was that no matter which of the three included sizes of silicon tips I used, the ear buds would not stay in my ears.
After trying to use them for two weeks, I gave up and went back to the original Apple ones.