I travel once to twice every month and I want to buy a pair of good noise-cancelling headphone so that I can listen to my ipod or get some rest . first , I try a Sony nc50 at a Sony Style store . the nc50 put out so much accoustic pressure to my ear and it really hurt . then , I try Sennheiser PXC-250 , pxc-300 , and Bose QuietComfort 2 extensively . first time , I bring both pxc-250 and pxc-300 to a trip from San Diego to Newark . there be no significant performance difference in term of noise canceling . the pxc-300 have a better case . then , on my next trip , I borrow a bose quietcomfort 2 from a colleague of mine and compare it with pxc-300 . after extensively testing -lrb- with and without music , with and without background people talk , and etc. -rrb- , I find it be about 20-30 % less of noise with bose . also , my ear feel warm and uncomfortable after 30 min with pxc-300 because of the over-the-ear style . I understand everyone else 's comment on bose be over-priced , but if you be look for the best noise-cancelling performance on a airplane , unfortunately there be no other way around it . bose be certainly the best .