The 737-800 without
the mid-cabin lavatory option. I am usually seated in the front of coach and the lav traffic and odor is bothersome. I do not know what percentage of the CO
800's have the mid cabin lav but it seems like about half.
I do know that the FA
's like the mid-cabin lav as it helps with traffic when they have carts in the aisle.
The 800's do seem a little smoother and more powerful than the smaller models. Also the winglet models seem to have a little more zip. Probably psychological on my part but they look good too.