Hi!

I've just flown on the A380 from CDG to JFK and back.
Upperdeck is the best, since it's a small cabin (only 109 seats) and have cabin attandants all for yourself. You'll be amongst the first eco pass to get of after flight, since only cabins in front are bus and have priority.

On the way back we were already put a sleep, while down downstairs they were still serving dinner

Also if you have the luck of booking a seat on either sides, you'll have the pleasure of only 2 seats and an extra compartment between the window and seat. Great for easy acces to your stuff, but also some extra space when you have to wait an hour before they pick up your tray again.

The A380 is a real experience I have to say. It was worth the horror of a connecting flight on CDG!