Interesting Pete. I'd heard mention of EK introducing P/E at some stage and I guess upstairs on the A380 instead of First would make sense.
I hadn't realised the seats upstairs in economy cost more but it might explain when we flew back to MAN in January why there was only 1 person in that section so 40+ empty seats. And they tried to tell me there were 600 pax on board! Downstairs looked full and Business certainly was with not a single spare seat.