I had a chance to test some px200 for several occasions, they didnt impress me at all in style or sound, i could compare them on the spot against my sony ex90 playing from a sony walkman and there was quite a difference, actually there where like 6 different Sennheiser cans of all sizes formats and prices, up to 200 or so €, all of them dissatisfied me, for some reason i didnt like the way they look feel and sound...
Also i use at home one pair of sony mdr-v900hd cans, the build quality is very superior to anything ive seen from Sennheiser and comparing audio quality, i had a chance to run several cans models from my own walkman at an apple store, im not sure i run the px from it, the only model that pleased me amongst perhaps over 10 cans was an B&W model i had never seen and i would love to compare with my 900HD...
Also while auditioning other small cans, i tried the small akg that where just at hands reach and it was rather enjoyable for its size, specially after being disappointed with the px...
Id also like to add that i tried the normal dr beats and found them average, but next to them where the bigger beats heavier but more comfortable and better sounding...
Sorry for the rant, but every time i read an headphone's review, i get the urge to start writing stuff...
By the way i bought my 900hd from ebay for 30€, people tell they are fake, but build quality is great and the only cans i could test that could match it are the beats pro (i like this model a lot) and the B&W (great visual, comfort and sound) and these cost 300€...
Im by no means an expert but i like the best audio possible (for the least money)...
end of rant