Summary: I always buy Sennheiser when buying earphones; the sound quality is always great and usually they last a long time. I listen to music almost constantly whilst commuting or at work so I put earphones through their paces. The problem I've had with these is that anywhere between 3 months and one ear of use; ~40 hours a week 48 weeks a year, the left ear bud will stop working. This is always preceded with a slight crackling in that bud until one day it just wont work.
Summary: As earphones, I can't fault the CX400 II. However, after six months, they are extremely tatty. The labels have fallen off. The decals have worn off. The sleeve around the wires has pulled out of the earphones, exposing the bare cables, and the plastic around the wires has started to flake off. Excellent earphones from a sound point of view, but terrible build quality.
Summary: These are the best cans you will find at this price. Warm and detailed sound with the signature bass of the CX400 range. I would not be put off by the negative reviews about build quality, as only after 4 years of daily use has the left earphone started to fade (and I did get sand in them). If you are paying this price or more for earphones I would hope people treat them better than those standard Apple pieces of crap.
Summary: I absolutely rate this product because of its build quality and sound. Sennheiser is a renowned industry brand for professionals. I used to have iBeats by Dr. Dre that came with my phone and within a couple of months they failed. This product is going strong six months on. I would highly recommend this item to potential customers who are looking for excellent sound and German build.
Summary: I previously owned a pair of CX 400 II, which lasted for ~2 years. When they finally broke, I replaced them with a pair of CX 175, which are ~£25, rather than ~£45 for the CX 400 II. However, the CX 175 were really disappointing and I had to return them. These headphones are great as they offer a richness of sound and depth that are not found in cheaper models. The rubber tips fit neatly in the ear, giving great sound without leakage.
Summary: These are great, great sound, great quality, great price Lots of spare pads of different sizes to suit each individual ear. They come with a soft pouch to keep them in when not in use. If I had to fault anything it would be the volume slider is a bit tricky to adjust with any degree of fine control, but that would be very picky.