Peter King (again)

I seriously doubt SI has anybody traveling first class, unless the writer is paying for the difference from coach.
Orbitz works just fine, obviously. I try to keep my miles with just one airline, so I can get upgraded here and there, etc.; often I just book through the airline's site. It's usually pretty reasonable.
I don't know if PK really flies a ton. From where he lives he can drive or take the train to a lot of NFL venues. Remember, he needs to be in the Manhattan studio every Sunday for that show he does. My sense is he travels a lot of miles to training camps, not that much during the season.

 

"Reportedly" was added after news started spreading that it may not have happened. PK initially "reported" it himself before hinting that there was another source.