In my experience CW upper deck window seats on A380 are pretty good in comparison with 777 (never flown 747 / 787 CW). A380 First is the best version with wider seats than other versions. For a very large price difference it's probably not worth the upgrade but for a small avios cost I'd definitely take it - better catering, better booze, better seat, a lot more privacy, possibly better irrops handling... 😎