I got 737 with new seats on this trip (both way). It was the most uncomfortable ones that I ever experienced in all those years flying. It was not the space (as Economy Plus gave me a few extra inches of leg room) but the problem was the seat itself. The bottom of the seat was about half of my upper leg length and lacked the support. it was "hard" because the seats were "thin." It was impossible to catch a nap even on the red-eye...