After trying out Emirates and Etihad in business class, I was very excited to be able to fly with Qatar on LHR-DOH-HKT and back. Originally it was scheduled as a 777 and A350 with Qsuite on both legs, then it got changed to A380 and 787, and then A380 and A330 - same on return.
The A380 was good, but not getting close to the A380 with Emirates or Etihad (if their A380 will ever fly again). No mattress was available on any of the flights. Also, the food was just okay, nothing impressive.
The A330 was, for Qatar standards, absolutely horrible. Such a cramped seat with no storage, the footrest only covering 1.5 legs because of the curve of the seat, and the window seat with a cable cover where your feet are. I felt more comfortable on a Ryanair 737 where at least your legs are free. Service was also rather slow and they seemed understaffed, it took over 2 hours after take-off to complete the meal service, and the food also did not taste great. I feel really sorry for people who stayed on this plane to continue to SIN or KUL, and it is quite shocking that Qatar is using these planes on an 8-hour route.
I admit my expectations were very high, but I would strongly advise anyone against a business class flight on the A330 if they have a choice. If I had the choice again, I would have canceled when they changed the route to A330s.