Here’s the next round in the continuing debate.
Bernstein Research published this chart detailing how Airbus and Boeing differ on the performance improvements they predict.
There is, of course, no way to know who is correct until the airplanes enter service.
We hear the A320 sharklets are performing better than advertised (Aviation Week actually reported this a while back as well). If the figure we’re hearing proves correct, the neo and MAX should have parity.