I don't think you guys realize this yet but the reason why the A320 is so popular among airlines is because it is foolproof, the 737 is much more complicated (system wise) than the 320. And it's not just the A320 but all series after it 330,340,380.
Also you probably haven't thought about how large an A320 is, once you realize that you are gonna be flying a plane with 125+ pax behind you, that don't know anything except for where the plane is supposed to land, then size becomes the least of your problems.