"Far superior to QC3's -- Battery a plus!"4.5 starson by jmdorw
Pros: A significant improvement in noise reduction from the QC3's, and I don't worry anymore about trying to get the "right angle" on my ears for best noise reduction. I actually like the battery system, since I've killed off my rechargeables on my QC3's.
Cons: Bulk, of course, is slightly larger than the QC3's, but to be expected.
Summary: These are my new favorite flying partners. I highly recommend them -- stick a couple of extra batteries in the case (convenient pouch to do that) and off you go!