the plan is to go from heathrow-san francisco, san fran to Washington, Washington to Boston and on to New York and back to Heathrow. United is coming out the cheapest at 750 per person, but having never flown them was wondering if they are any good.
They have told me that it will be a 777 outbound and a mix of A320,319;s internaly and a 767 back, do United operate the 747 in to heathrow and I thought we would be coming back on a 777 not a 767.

I think UA only operate the 747 to IAD from LHR.