I had a pair of Bose QC2 phones and thought they were the box deluxe. The QC2s are a bit big and when the lead needed replacing I thought I'd give the NC250 phones a go. I must say that I am very impressed with them. You are able to use them with the noise cancelling switched off which is an advantage over the Bose QC2s. With the NC switched on, these cool looking phones really come to life. Deep Bass, good treble and a boost in volume that brings the sound on my Sony mp3 player to a good level. The noise cancelling is as good as the QC2s and damps down the noisy deisel engine of the Transit van I drive. They are just about small enough to wear outside without destroying your street cred and look good in metallic black. The lead is shorter than some phones but for mp3 player usage I think they're fine. A new longer lead is easy and cheap enough to buy as it's a standard stereo mini jack. The battery needs replacing about as often as the QC2s after something like 20hrs. The first time you insert the AAA battery in the right ear cup it's a little tricky, but it's not that difficult and I can do it blindfold now (not that I've tried!)
Overall I'd say these phonesare as good as the Bose QC2s and at only a quarter the price, well worth the money. Highly recommended!