Upgrades we'd like? How about a 777/787, or at least a 757/767, level cockpit?
Flipping packs on and off, openning valves, selecting generators, auto trim(and trim wheel) that goes nuts, etc, etc.
Oh, how about 757 windows and field of view, especially for noise? And moving your kitbag farther forward? There are lots of improvements that slapping a 757 nose/cockpit on the 737 would have helped. It came down to $$$ and SW's foot dragging.