Adding to the chorus who prefer AA90 (the daytime flight). Staying up and working through the day - especially now that the Panasonic Wi-Fi has become more reliable across the Atlantic - has significantly eased my jet lag going east. Personally I'm a fan of the Hyatt Place on Bath Rd which has a pretty decent breakfast buffet each morning and an easy public bus connection from T2/T3, but staying anywhere along the Elizabeth Line is rather convenient as a bridge between the City and Heathrow if you want the day to putter around London.

AA doesn't have a J seat that can beat sleeping both nights in an actual bed.