USMCProbe, I guess the question would be is "full" for A321 the same "full" as for the 737-900ER. Are we talking about the same payload/ number of passengers. The A321 has a longer cabin and bigger cargo bay to start with.. The 737-900ER has a bigger fuel tank that carries it further when there are very low payloads (17k t).
I think a weakness in the A320 series is the big diffrence between the A320 and A321. It seems they skipped a sub type. Both the 737-800 and 737-900 fall inbetween the A320 and A321 capacity wise. Big Airbus customers Ryanair, Easyjet and JetBlue asked for a 200 seater. To no effect so far.. Maybe if the Embraers NG/ CSeries burry the A318/A319 they'll move
