almost everything that can be say about these headphone , have be say , so I 'll keep this mostly to physical pro and con pro : the most accurate sound you can get for 100 dollar . not up to par with my beyerdynamic dt880 's , but at one third the cost , you be get atleast 3\/4th 's the sound -lrb- if that make sense -rrb- so they be a excellent bargain . these be easily the best headphone you can buy at 100 dollar . the velour ear cup mean that the pressure apply to you head be very minimal , and these be indeed the second most comfortable headphone I have ever worn , next to the dt880 's -lrb- I have have Grado 's , AKG 's , other sennheiser etc -rrb- and the inclusion of a velour -lrb- I believe -rrb- head cushion mean that the top of you head will not hurt even after hour of use . these can be also very easy to drive from a pc soundcard , and even on my integrate sound card , they 'll go to ear splitting volume if I be so inclined . I buy these specifically because my beyer 's can not be drive by my computer , and I get sick of have to move my headphone amp between device -lrb- between Ipod , computer , etc -rrb- . the Bad : a all plastic frame make I think that one good drop might be the end of these headphone . the ear piece be attach to a swivel joint -lrb- for comfort , which do help -rrb- but the joint be plastic as well , so it be not hard to imagine it pop off . I may just be worry too much though , because I have a pair of all purpose koss headphone that be entirely plastic , and they have last atleast 10 year -lrb- though they sound terrible in comparison -rrb- I say these be the second most comfortable headphone I have ever worn , and while that be true , there be one caveat ; even though they be comfortable , my ear be too large for the space provide -lrb- the velour sit around the ear , with you ear inside -rrb- so my ear press against the outside of the ear pad . not a huge deal , and not nearly as severe as with other headphone , but still a issue if you have big ear . the biggest complaint I have be probably how much sound leak in and out . I realize that these be open headphone , but even at low volume , everything you be play be easily hear by anyone in the same room -lrb- so these be not good for dorm room , plane , train , etc -rrb- . I be expect that , but I be not quite expect how much sound be let in . my dt880 's be also open , but they do not let nearly as much sound in or out as these Sennheiser can . the sound of my computer fan be easily hear through the headphone if I do not up the volume a little louder than would otherwise be necessary -lrb- mean other will hear it even more -rrb- . there be also a lack of bass with these can . other have say it be balanced , but I would almost go so far as to say it be a little bit diffused . use equalization though , this problem be quickly fix -lrb- if you see it as a problem -rrb- . one last con ; these headphone come with a large -lrb- 1\/8th inch I believe -rrb- plug , with a very rigid 1\/4th adaptor -lrb- the plug on you computer , compare to the plug on you stereo -rrb- . this do not seem like a huge deal , but this type of adaptor be very prone to snap and damage you headphone cord . I would suggest spend a extra 5 or so dollar and get a flexible adaptor . as with all headphone in the quasi-audiophile range -lrb- audiophile will tell you that these can be not neutral enough to be audiophile quality . they be close enough at 100 dollar though -rrb- you first need to evaluate you own hearing before you spend any amount of money . I have friend that can not tell the difference between my 300 dollar beyerdynamic headphone , and my old 30 dollar Koss headphone . if you do not have really sensitive ear , you be better off buy the cheaper sennheiser and save yourself some money -lrb- the 202 's , the 212 's , etc -rrb- . I would suggest go to a local audio store and try these headphone side by side with a much cheaper pair , and see if you truly can tell the difference between the two -lrb- and then come back to buy from Amazon , of course -rrb- . also , if you do not buy a whole lot of CD 's , and most of you music be compress mp3 's you buy off the net , or song from youtube\/myspace\/whatever , these headphone will not help you and they may actually make that type of music sound worse because they will expose flaw in the recording that you would not have be able to hear otherwise . in conclusion , these be the best headphone you can buy at 100 dollar , and unless you need complete isolation -lrb- if you do , I suggest the hd-280 's for the same price -rrb- , or you really love bass , or you have really big ear , these headphone be exactly what you be look for . update 03\/10\/10 : after two year of use , I have get a few addition to make . the headband have develop a crack at both ear cup . I baby my equipment , so it be definitely a design flaw and not misuse on my part . I have notice that this have happen to other as well , and it really be a shame . it do not degrade the sound quality , but I fear that the crack may expand and eventually cause the earcup to come free from the headband -lrb- essentially make the headphone useless -rrb- . as far as sound quality go , now that these be burn in -lrb- I would say I be somewhere comfortably between 500 and 1000 hour on the phone -rrb- they sound much better than they do when I first receive they . I modify they -lrb- when I pass the warranty date -rrb- to increase they bass response , and they be now basically convert into hd595 's . they sound great , although they be still obviously no match for the hd600 's or hd650 's , which be 3-4x the price -lrb- much much more when you consider that you 'll need a expensive amp to drive they -rrb- . I would still recommend these headphone despite the crack issue , and for 100 dollar , I do not think that you can find a better set of -lrb- open -rrb- can .