I might be in the minority here, but I prefer the e2c. As I commented in another thread, the cx300 has more extended high frequency response than the e2c, but the bass is more defined on the e2c, and my impression is that what the e2c does reproduce, it does better than the cx300. The cx300 has fizzy highs, a slightly attenuated midrange, and an undefined bass that doesn't differentiate between different bass notes. It sounds pretty decent for simpler passages, but it gets messy when there's a lot going on. The e2c has pretty decent bass for an earphone that goes lower than the cx300 and a very good midrange that excels with vocals. The e2c's achille's heel is that the high end is a bit rolled off, but I find that it's actually kind of pleasant and allows for longer listening sessions. The e2c also has the advantage of providing more isolation and no microphonics. Comfort might be an issue at first, but you should be able to adjust within a week or so. I personally think that there's enough of a difference is quality to justify the premium for the e2c, but others seem to be content with the cx300.