Can someone please tell me what makes the 737Max so great? It doesn't look like it beats the 321Neo in any meaningful way. I've been looking for comparisons but haven't really found any decent discussions based on metrics.

For example, can it takeoff with a full passenger load or will you have to deplane lots of paying customers? I hear this is a problem with the later model 737s.

Is there more room in the cockpit yet?

Is any of the flight control system more advanced than 1960's technology?