Upper deck without doubt. Much quieter, even though its a very quiet aircraft anyway. Window seats have MASSIVE bins to store stuff. I flew CW to JNB on the 380 a couple of weeks ago and was in 59A, which is the last row in the upper deck CW, and was excellent, with direct aisle access. To be honest, I have felt for a long time that the old CW seats are far more comfortable for sleeping than the new Club Suite, as the latter seems to have a hard horizontal bar which I find digs into my back. Given that the window seats have such massive storage bins, that really helps given that the old CW seat has very little storage space.