Before buying my QC-2s about a year ago I tried several models from Panasonic, Maxell, Sennheiser, Sony, etc. I tried over ear, on ear, and in ear types and ultimately found that the QC-2s really did do the best job for me and had the best combination of comfort, sound quality, and noise reduction (YMMV of course...). Recently I was at the Bose store at PHL and did a side by side comparison of the QC-2 and QC-3. The QC-2 absolutely blocks out more noise than the QC-3 when I wear it. I also found the QC-2s to be more comfortable, even though they weigh more than the QC-3s. The physiology of the wearer probably has a lot to do with comfort and the degree of noise reduction due to fit on the head and the seal over the ears that is created.