QC3s are way more comfortable than QC2s and work just as well in reducing noise. I tried both for a month each, flying cross country roundtrip each week before deciding. Bose has a 30 day trial period so you can judge for yourself.

IEMs like the Shure e4c I have block out noise much better than either (like earplugs), but are a little less comfortable. They are worth checking out though.