First off... I want potential buyers to be aware that the people downgrading (1 star) these headphones for their quality are complaining that the headphones CRACKED after YEARS of owning them... The only problem, is that these headphones have only been out for a little over a month. I suspect that they made an honest mistake, and have the old Bose QC2's (QC15's are the newer version) which were notorious for their cheap construction on the headband. I have only had mine for a few weeks so I cannot comment on the durability, but [...] wrote in their review that Bose had made adjustments to the headband (new design + materials I believe), and that the durability should no longer be an issue. Hopefully that is that case.
On to the review:
I went on a little shopping spree and bought the JVC HA-NC250, Klispch Image S4, and these guys (QC15) to compare them. I don't consider myself an audiophile, but I am really picky about electronics purchases... even to a fault. I am a medical school student, and obviously don't travel extensively, but I want to be able to study at home without being distracted by my wife's music/tv/neighbors/etc, so I was in the market for some noise cancelling/isolating headphones. The reason I chose these three headphones: JVC were cheaper noise cancelling with decent reviews ($[...] now), the Klipsch Image S4 ($[...]) got AMAZING reviews on CNET for sound quality, so I had to see if they blocked noise sufficiently, and these were the "top of the line" headphones that I wanted to try to see if they were worth the money.
Regarding the comfort of these headphones... ohhh baby. The material that they use for the earcups is AMAZING. No clue what it is, but it is extremely plush, without being obnoxiously huge and pillowy. I have worn the headphones for 3+ hours listening to music while studying with no discomfort, although my ears do get a little warm. It is not really uncomfortable to me, but I could imagine if I were in a really warm room, it might be a nuisance. I have used multiple types of earbuds, on ear headphones, and over ear headphones, and these are by far the most comfortable I've tried. Klipsch are earbuds, and fit VERY securely, but after a while they just annoy me (30+ min). JVC are more comfy than the Klipsch, but get destroyed by the Bose. QC15 win, hands down.
Sound quality: In my opinion, the Klipsch earbuds sounded the best, but I think that is partly due to the extremely secure fit and tight base that is produced as a result of having them jammed in your ear canal. The obvious downside is that those bug the crap out of me after 30 minutes of use. JVC sound quality is NOTICEABLY worse when the noise cancelling is off, and good when it's on, but I found the base kind of shallow (the battery compartment is not a pain to access like some people seem to complain about... unless you have gorilla hands). Bose sound quality seems VERY balanced. Exceptionaly clarity, responsive/tight base, and no hissing in the background. I did notice a little hissing when I was listening to classical music at near max volumes, but who listens to classical music at really high volumes... and it was most likely due to the sound quality of the song (download from Itunes) and not the headphones. Overall, outstanding sound quality for the QC15.
Noise cancelling: Bose > JVC > Klipsch. Obviously the klipsch aren't designed to eliminate sounds, just muffle them, and they do that well, but not well enough, and as I said before, I find earbuds slightly uncomfortable. The JVC headphones had notably worse sound-cancelling than the Bose. It is partially due to the fact that they are on-ear instead of over-ear headphones (bose). With the same song at equal levels I tested out both headphones while vacuuming (obviously VERY loud sound). JVC probably knocked out about 50-60% of the sound. The eleminate LOW frequency/pitch sounds very well, but ALL of the high ones that aren't muffled from wearing the headphones get through. As a result, I could hear the whine of the vacuum extremely clearly. QC15's easily eliminated 80+% of the noise. All of the low frequency sounds were dropped, and the higher frequency sounds were noticably reduced, but not gone. Of the 3 headphones, the bose is the clear winner.
While I know these are obnoxiously expensive ([...] bucks for headphones is ridiculous...), I have been very impressed with these headphones. Only gripe other than price is that noise-cancelling technology in general is unable to reduce high frequency sounds as much as I would like. With that said, I believe that these Bose headphones provide OUTSTANDING comfort, exceptional sound (aparently some audiophile people complain that they don't match up to their 500+ dollar shures, but w/e), and among the best noise cancelling money can buy. Also, it's wonderful that they changed over to a AAA instead of the stupid proprietary bose battery. If I were a frequent flyer, these headphones would be a no brainer.
Kept the Bose, and the other two got the boot.
(Quick side note... I have a pair of Sennheiser CX300's [earbuds], and for < 20 bucks you WILL NOT find a better pair of headphones. Comfortable by earbud standards, amazing base, clear mids/highs, unbeatable price. I use those for running, and the Bose when studying)