I think his point was that with only 20 years left, WB's are out of reach... so it's basically only 737 at that point.

This thread may be mind-numbing for some, but I have found it incredibly informative. As someone with a ~20-year career ahead with a toddler and another on the way, it's been enlightening to learn the areas where WN outperforms UA. It turns out that they are quite important to me. Thanks to all for sharing.