I definetely enjoyed my 12 hours in the F lounge in concourse A.

http://www.flyertalk.com/forum/emira...ess-class.html

I think every first passenger should try it one time. As to what to do in the lounge during this long-over stop, you can:

1) Watch TV
2) Use the business center and surf the net or youtube
3) Take a shower
4) Enjoy the food provided in first class (it is delicious)
5) Try the complimentary shoe-shine & 15-minute spa service
6) Enjoy the view of the tarmac
7) Experience what it feels like to sleep in the F lounge in Dubai
8) Talk to fellow passengers if you get the chance
9) Relax in the meeting room next to the business center
10) Watch the flight departures screen.