My experience with QC2 is mixed. In BA flat beds they become uncomfortable if I lie on my side, as the pillow is pressing the headphone hard against my head. My ears also become a bit hot after several hours and I often take them (the QC2s that is) off after the first few hours of drink-induced sleep then sleep another two or three hours without the phones. All in all I'm not sure they really add much value in the lie-flat seats. As headphones for using to listen to an ipod or whatever they are great. I haven't tried to sleep with them in a more upright position but imagine at lying on my side problem at least wouldn't happen. I'd have expected similar effects with the QC3s.