Having been a marketing casualty years ago by the Sennheiser headphone giant having two decent over-ear headphones bought of them, I decided to have these for an MP3 player additionally seeing good reviews about them.
 
I don't know if eartips of them not fitted well in my ears but the sound was awful!!!
 
I can't say enough about mids, trebles, basses etc. but overall the sound was harsh to a point that my ears couldn't stand the dreadfull noise of them!!!
 
As I was a newbie in IEM's it was a traumatic experience as it was difficult for me as a music user to buy another in-ear after them.
 
As I pre-wrote I hope there were the tips not fitted well in my ear canal because I didn't expect such a drawback from the Sennheiser company.
 
I don't recommend them at all!!!
 
(A day before the review I tested (without burn-in and Comply foams where I am an admirer) the Philips SHE-3590 and they are much better than 300's and they cost lower than 10 euros!!!)
 
Anyway, test them before you buy them.
 
Have a nice life, yannisgk.

I had many expectations of these IEMs but unfortunately besides the great design of them they proved to be just overpriced.
 
Listening through an iPod shuffle (4G) I had, in the beginning I thought that something wrong was going with it. After using Comply Whoomp the sound was slightly better but the sound was harsh too.
 
The last try with them came through listening to a new-bought FiiO X3. LOL!!! The harsh sound was audiophiliac now!!!
 
Because I don't have many experience in IEMs or HPs overall I gotta say that a cheapo (7 and a little more pounds) Philips IEM pair of phones I have it's much better at least in soundstage (even though it's darker-sounding than the Apple's In-Ear).
 
My overall experience with them was decent but I recommend them only as a collectable product.