It should also be noted that UA uses a B777 for one SEA-ORD and ORD-SEA flights each day! (Although I hear this is being discontinued soon)

While I didn't fly in First, I was upgraded to Business Class on a B777 setup for international flights. Business class was far SUPERIOR than AS First class.... no contest. Massive seat pitch, seats recline waaaaay back, full leg and foot rests, personal video monitors (multiple channels), back massager built into chair (although it didn't do much IMO).... anyways, I was ready to switch all my flying to ORD to UA.

However, I learned that triple-7 service between SEA and ORD is being discontinued... although they will still have 767 and 757 service.