I run and bike quite a bit and needed a good pair of headphones to rock on to while running. Most headphones outside of the standard Apple headphones really suck when running. There is cable noise, which is scratching when the cable is in motion. I had a pair of Sennheiser, that were marketed as Sport, and still had cable scratching while running, which ruins the audio. It's like static while talking on the phone. Other pairs of headphones don't fit snugly in the ear and fall out while running, which is also a no go.
I previously had the Bose IE2, which are fantastic headphones on their own right, but they are quite brittle. After two years, the headphones are fraying at the ear pieces, there are rips in the cables, and I'm sure they will die any day now. If only I could have the IE2 but with more cable reinforcement! Welcome the Bose SIE2 - essentially the "Sport" version of the IE 2.
The Bose SIE2 headphones are a neon green color, which I don't quite like but they will do. There is significantly more cable reinforcement in these versions than on the IE2, which makes me more confident that they will last longer than my IE2 pair did. The ear pieces fit more snuggly than the IE2 does and also feel more rugged. After a run and bike in the wind, I can say they sound just as great as the old IE2 did, and have somewhat better noise isolation. I hear the outside world less with these than the standard IE2. The Bose SIE2 has zero cable noise and are water resistant, which was helpful after using the supplied arm band. Great sound, good cable strength, and zero cable noise, what more do you want in a pair of running headphones?
The only gripe I have is that the cable is either too long or too short. The package comes with the headphones plus a cable extension. Without the extension, at 5"10, the cable tugs at my head when my iPhone is in my pocket. With the extension, tons of cable flaps in the air during a run or a bike ride. Outside of the cable and the color, the Bose SIE2 are great running headphones. Now if only Bose would make the Bose IE2, same cable length and color, with more rugged cables! That'd be perfect.