I travelled MH123 KUL-SYD A330 business class arriving SYD 7 Aug 2019 (landed early then 1+hour on tarmac waiting for gate). If travelling alone I recommend the A seats as these are single seats window and aisle access and select the even numbered seats (2, 4 or 6) as these seats are positioned closer to the window with the table and stowage cabinet on the aisle side. I have selected 1A previously and found my self being bumped by trolleys, you need to keep your elbows and fingers within the seat space to avoid injury given the odd numbered seats (1, 3 and 5) have you positioned closer to the aisle with the table and stowage box between you and the window, making it more difficult for crew to reach table and for you to look out window. Also note, other than the small stowage box, there is no stowage space for a small bag or a laptop, everything has to go in the overhead. 1A is also more prone to injury as it does not have the protection of a seat in front and the bulkhead doesn't cover the seat fully as the aisle is slightly offset to the galley entrance, so the trolley seems to be heading at you as it comes from the galley. I agree with other comments, much easier to sleep on side than on your back, just be aware of your knees protruding onto aisle in the odd numbered seats as mentioned. Downside of the window seats (both sides) is that its impossible to see the screen when in the flat position because the cabin lighting positioning reflects perfectly off the screen to your head position when lying. The screen has no tilt adjustment (as found on most other airlines) and the crew insist that the cabin lights causing the reflection on the screen must remain on at all times. The design of the seats and configuration is appalling, consultation with someone who has travelled on a long haul flight may have been useful, just sayin'.
I note the A350 has similar seat configuration issues, however if configured with business suites, they take row 1, which means you want to avoid 2A being the bulkhead in business class and opt for 3A or 5A or those where the seat is closer to the window and the table on the aisle side of the seat. MH A380 has none of these issues and is by far a better experience.
