I just flew A380 in the peak xmas/new year time from LAX-DXB-LAX. Every single seat was occupied but there was plenty of overhead space. There are EK staff standing in the jetways trying to take larger cabin baggage for baggage check-in by force. I saw one guy arguing that he wanted to take his bag in but they didn't budge.

The boarding zones are C, D, E, F, G, H and I have boarded in G with plenty of space available.