Chicago O’Hare is the biggest hub followed by Newark then LA, Washington and San Francisco
But usually with overlays there is no time to see anything much as get in at night, have minimum rest and up with the sparrows next morning to do it again. It’s a 4 day cycle leading to some days off for rest. Typical line is 16 days of flying per month.
And there could be some short reserve days (2 hours to get to airport in your domicile) and long reserve days (12 hours to get to airport anywhere in USA).
Btw, 760 aircraft in the fleet and there are lots of Airbus). But usually Boeing crews are cross endorsed with other Boeing and Airbus crews cross endorsed with other Airbus to keep things simple for their training and for the pilots.
Plus there are a heap of B757s which is awesome. B767s are approaching end of life, then the B777 and B787.
Speaking about sexy planes. That B757 is just as sexy as they come.