The 757's are great aircraft, my personal favorite, but they are being parked because some of ours are very old. They are not being built because no one was ordering them.

700's and 800's are capable, but I think the 900 and ER are not a good fit for N America. We have too many small, inner city airports. They are fine for Asia where most runways are sea level and 12k + feet.

Our 320's are getting up there as well. The 320 and 321 that you can take delivery of today, are more capable than UAL's. They are much less performance limited than 800 and 900's.

I think the 900's are a mistake. I will take a 321 any day.