I fly business LHR to Doh to HKG every month on qatar, average price £1550 + tax. first leg is ave 5.5 hrs, then 1.5 hr layover then 6-7 hrs to HKG ,depending on the weather. I have been doing this for past 3 years and apart from a couple of niggles (never choose row 7 on the 777, the power points dont work)
the last flight I took is 777 first leg which is full length layflat with massage etc. food as always is excellent. 2nd leg was the A330-200. while the seat is flat its still slightly angled a few degrees, but it has probably 12inches less legroom as well as less cubby holes for space.
The doha lounge is excellent however if the aircraft parks on teh east of the runway its a good 15-20 mins to get to the terminal, which if you have been late out of LHR as I was thsi time can make you sweat a bit on connection. however I havnt missed a flight yet and in the past they have delayed the HKG flight for people to get on. in LHR they use teh skyteam lounge which is ok, not fantastic but ok. can be a bit hard to get a seat sometimes, this time I had to ask someone to move thier bag as they her seat holding. he didnt seem too plaese about it!