The F lounge is very comfortable but not for sleeping. If you have a conx over 8 hours EK will probably pay for a room at the Le Meridien if you request it. However, I prefer to spend the money myself and book a room at the airport hotel in the terminal. It's right above the F lounge & you'll get SN extra hour of sleep as you won't need to clear customs & immigration not to mention the drive to Le Meridien