Having taken both airlines......numerous times......I now only travel to Hawai'i on CO. Why? Check the following address for a comparison of both configurations: http://www.seatguru.com

With this information you will notice that CO has the finest domestic seating opportunities, with 3/4 flat seats. As a choice I make when I fly, seats are Number One, and Number 2 is the type of aircraft. It doesn't matter if it's a 757 with flat seats....I won't fly in a clostrophobic, elongated tube! The 767 isn't the 747, but it'll do nicely for my flights over 6+ hours.