I live near MAN in the UK, and compared to the sheer, heart-busting, stress-inducing hell of connecting at LHR I would much prefer to fly into the US on one of the UA flights from MAN to EWR or IAD and continue onward from there. I get my booze in the lounge and have my entertainment on my iPad.
Smiles from the FA's? Don't care. I'm either asleep or watching a movie.
Bad meals? Don't care. I've usually eaten at the airport.
I've often been told that I could fly to the US via FRA, DUS or MUC with LH but it's honestly not that much different when you're in Y. Besides, as a *G I can usually spring a seat in Y+ on UA free of charge. Even if I have to pay for it it's still cheaper than LH.