I'd go for 80AB/JK on the A380 without a doubt. Completely unlimited legroom, much smaller cabin, I had it on an overnight back from SIN last week and it was so quiet. Loved the mini-cabin, and the service back there seemed very good. The main 3-4-3 cabin on the A380 seemed quite claustrophobic to me. I'd never go for 25D- even after seeing it myself I think it seems a little overrated compared to rows 70 + 80 ABJK on the UD which offer a lot more space.