Bought these as a cheap iem to use while my customs are being fixed, they sound pretty good for the price, isolate well enough to be bearable on the train, and weren't too expensive.
My problems with them come from the entire design of both the iem's and the product as a whole.
Plastic death packaging is awful, physically getting the phones out of the package was infuriating, rather than a pleasure, even with scissors, and a stanley knife.
enclosed where the earbuds, 2 extra sizes of silicone tips, and a plasticy pouch with a metal snap close ala sunglasses cases..
The pouch offers little or no protection for the buds, thoughtful, but pretty useless really. iems are easily damaged, that seems to be a fact, so a hardcase is somehting of a must in my books. even at this price point. Logitech can do it, so Sennheiser damn well should too.
The cable feels cheap, flimsy, and generally disgusting, I can't comment on it's durability yet, but it doesn't look promising. Even more annoying is that the length of cables after the splitter is whack.
The left bud has around half the cable to the right, so I'm forced to wrap the right around the back of my neck, this is both annoying, and dysfunctional. Why they do this is beyond me, it just makes them less convenient and comfortable to use.
Finally, is something that seems to be a theme with sennheiser products.. The 3.5mm jack, is right angled (which I like) but it if freaking huge, I can fit my index finger between the gap it makes with the player, that is totally unnecessary and seriously annoying.
I wouldn't recommend these to anyone, even if they sound good, they're horribly designed in my books,
finishing on a good note, they are at least comfortable IN my ears, even if the cable pulls unevenly on them.