I am usually in 11K. The back cabin normally has less passengers, less attentive service.
You may get quicker meal service, since you decide how fast you go through your meal. However the FAs still have to serve other passengers, so there will be serving traffic in the aisle. Expect at least 2 hours after departure before they turn down the cabin light (after duty free sales).
They start turning on the lights for refreshing meals about 2.5 hours before landing, you may sleep through and have your meal ~ 1 hour before landing.