These are great for the active user. They will not blow you away with their sound, but you sure as heck won't have to worry about them falling out of your ears. I use them for running, working out, and mowing the yard, and they perform admirably. I have roughed them up a bit as well and they seem very durable. I found these open box on ebay and got a great deal on them. I wouldn't necessarily pay the $90 they are asking on Amazon for them. If you are looking for a set of buds that won't fall out of your ears during lots of activity, then try to find yourself a deal on these. If you are more concerned about stellar sound quality, then look elsewhere.
Sennheiser CX380 Sport Series II Noise Isolating Earphones - Reviews