I purchase these a few week ago and use they almost daily since . over the past holiday weekend , they be wear on a cross continental airplane trip and otherwise , daily during a one-hour one-way vanpool commute as a passenger . I also own a pair of bose qc2 headphone . during the trans-continental trip , the headphone be hook up to a portable laptop computer while I watch download YouTube video . -lrb- my laptop have a 5-hour battery life , so I watch video the whole trip . -rrb- on my daily vanpool commute , I attach they to either a ipod or a itouch , primarily listen to language training rip -lrb- at 128 kp encode -rrb- . 1 . the noise canceling of the mdr-nc40 be not as good as on the bose , as a qualitative side-by-side comparison . that be to be expect , consider the respective cost between the two unit . 2 . after about four hour on the plane , the mdr-nc40 headphone start give I a pressure ` headache ' . they be not expandable to the point that they be comfortable wear for that much of a extended time . -lrb- I be fairly large , 6 ' 3 '' tall , weigh right at 200 lb . and wear a fairly large hat size , 7 1\/2 , I think . -rrb- for ` normal ' size people , this may not be a issue . 3 . do not care much for the battery arrangement on the mdr-nc40 . it be somewhere in the middle of the single cord and contain the on\/off slide switch as well as a momentary cancel button . what be that for anyway ? you can hear people talk anyway . the battery box do have a clip that allow easy attachment to a shirt , so the weight of it do not pull down on you head . 4 . I like how they fold up and store in a smaller pouch than the bose . +1 for the Sony on that account . 5 . be wary , however , that the two-pin airplane adapter be easy to lose . not much hold it into it dedicate pouch inside the storage case . Mine fall out tonight on the vanpool ride home , but luckily , I notice that it be miss and find it on the floor of the van after everybody else have leave . I give it four star for the price\/performance , but have to detract one for be too tight on my head and cause discomfort . I 'll keep they for the wife to use and I 'll use the qc2 headphone .