Originally Posted by christep

Unfortunately, reports recently say that at least some of the LHR flights are of variable quality in F these days. To be safer (on service quality, although in a cabin that most people regard as inferior, albeit with the same seat) try to go for a CX flight served by A340s (although if it really is a day trip then you'll have a problem in that the A340s do the daytime HKG-LHRs and the 744s do the late evening departures).