Re the 739 to Hawaii remember that both ATA and Aloha fly the 738 and 73G respectivally out of several Calif airports to Hawaii including the short runway at SNA. I realize PHX is further east than Calif but still, u never know.
On another point I personally prefer flying on the A320 family than the 73G family and I no comfort level is even a stronger differance on the flight deck. But unless the new 321's already on order have significantly higher rated engines and MTOW than the current ones I just can't see how we can not order the 739ER for transon flying and especially high demand routes out of LAS where the 321 can't seem to cut the mustard in it's present form.
If I where running the show I would make the entire narrow body order 739ER's and since this is supposed to be a 733/734 replacemet aircraft let many of the 319's and 320's currently doing long hauls out of PHX and LAS plus other west coast markets replace the 733 and 734 and the new 739's replace the current East transon flying Airbusses and west long haul flying out of HOT airports in PHX and LAS that could use the boost in capacity.
Again my two cents.
LGA777