Pros: Cheap. Sennheiser logo. Nice carrying pouch. Average build quality.
Cons: Bad ear-fit. No bass if cannot fit properly.
Being a user of in-ears for a while, I've grown accustomed to great bass and some degree of outside-noise blocking. I bought these because I wanted to be a little more aware of the outside noise, so I could actually answer when people called me, instead of seeming disrespectful.
The sound quality is average, provided you can actually get them to fit your ear-cups. Outside of the part that presumably holds the diafragm and magnet array in place, there's a protuberance, for which I can´t seem to find any use except as working as some kind of bass-tube. However, this is the very part that hinders from pushing the part that's supposed to fit right outside the ear canal and get a snug fit. Sadly, this causes the lower tones to become almost completely absent if you can't "seal" with a considerable amount of pressure the earpiece. Prone to get lose with movement, too.