I will be flying on a UA 777 from EWR to LHR in June. It's been satisfying to read about the discussion as to the best seats on the 777. On my upcoming flights to LHR, UA has already installed Economy Plus seating. I did reserve 30A due to the spacious legroom in that row. I'll check the Economy Plus rows and report on its quality and effectivness after my return.
Save travels.
------------------