I have owned the grado rs-2, ultrasone pro 900, ath-esw9, ath-esw10jpn and ath-m50. All very expensive/ professional headphones. I'm on my fourth pair of shp-5400/01 and using them since 2008. Broke a pair, used one until it died (didn't bury it just yet), have one spare and using the shp-5401 for a half year now (better looks). The 5401 actually, possibly saved my life one time. Fell off my bike and landed really hard on the side of the cup. A chunk of plastic broke off, but thanks to the very comfortable cushions I survived.
Anyway, off topic information. There is a very good reason I'm currently on my fourth pair; that is because I really LOVE them. Yes, love them. Why, you say. Because a) I bought two pairs for 7 Pounds and 15 Euros, respectively and the others slightly more, though neglegible. b) The SQ is remarkable, I've stressed this quite a few times in an other thread. The lower end is fast, tight and deep. Supposedly Philips has implemented a special 'bass-technique', which actually works
really well. Mids are nicely round and full and do not get muffled, at all, by the lower end. Highs are crisp and clear, definitely non-fatigueing. All in all a great balance for a small price. Which brings me to my last point. I didn't enjoy the much expensive, high tier cans as much, because they basically didn't live up to their price. These do and much more. I even would go as far saying that they can hold their own easily against the ath-esw9, which I found not nearly as impressive. You can't go wrong with these. Buy them, love them and... Buy them again, like I did
Note: Make sure you burn them in for at least 50 hours, prior listening to them.