Pros: isolation, loudness, durability, comfort, bass, whatever you hear seems to be clear and balanced.
Cons: small soundstage, price
firstly, i think, these earbuds have 9mm driver instead of a 13.5 mm one, which may be a reason for smaller soundstage. for the price, i expected a better soundstage, ex300s cost less, yet have better soundstage. The bass is good, goes low. highs and mids sound good too. SOME PEOPLE SAY THESE ARE MUDDY AND BOOMY, BUT THESE AREN'T CX300, THESE ARE CX300-II PRECISION. The sound is balanced, with nice bass. Not much detail though. but, a balance and clear music experience. Highs are sweet. burn-in helps these to become more balanced (could be an illusion).
The build quality is fantastic. The size is small, fits well, perfect isolation, comfortable. The cable isn't flat, but not very hard to untangle. They lasted about an year with me, but i am not good at taking care, i bitten on the wire while listening, i caused a lot of damage to them. at last, the left side stopped working, whereas the right side sound was as good as new.
they could get 5 stars if larger drivers were used, like sony does. larger drivers make noticable difference in sound.