The new Sennheiser CX300 ear buds are Sennheisers answer to a market that has long been dominated by the likes of Sony's MDR-EX71 and various rivals, like the JVC HA-FX55. To me, a lot of these earbuds offered reasonable if not particularly great sound quality, often suffering from a recessed midrange and mainly being good if you use older ipods with their well known bass deficiency problems. There are also the more upmarket phones, like the Shure E2C and Etymotic ER6i etc... and then you can get even higher end ones, however, that would be missing the point... Previously to this, I have used Shure E2C, JVC HA-FX55 and Sony MDR-EX71. The CX300 cost me £32 from discount discs, so that puts them just £2 above the EX71. Trust me when I say, these are worth it. In fact, they absolutely destroy the Sony's, and JVC's. Compared to the Senn's, the Sony and JVC have undefined bass, and no midrange to speak of, and harsh treble, and generally sound unrefined. Compared to the Shure, well I think these beat the Shure's as well, it makes those sound a bit muffled and midrange recessed as well. The only area the Shure's beat them to my ears is isolation, where because of their design, the Shures attenuate a bit better than the Sennheisers. From what I have heard of these, you may well have to spend £100 just to match the overall sound quality of these when it comes to earbuds. In fact, it comes fairly usefully close to my full sized Beyerdynamic DT531 headphones: OK, so they arent as good as those, but the Beyers are full size - so they should be better. The Beyers are more comfortable, and are better in every sonic area, but not MASSIVELY, just noticably. You would never pick the Sennheisers over the Beyers, but you would NEVER wear the Beyers in public, unless you didnt care about looking like a total prat, and didnt mind carrying a pocket amplifier to go with your ipod! In short, if you are looking for a reasonable pair of portable headphones, you should put these at the top of your list, and frankly, not even bother with any alternative that may cost much less than £100, IMHO :)