My husband and I flew to LAX 9th October F, definately need 4 hours, just to be able to enjoy visiting the Gallaries, then into F lounge, to wander around, found the champagne bar area, so rested our weary feet with a glass with some kettle crisps, and then decided to return to Concorde room where we had an hour before left our cabin luggage with the left luggage man, this we felt was a lovely area, and sat at the bar, had a couple more glasses of champagne, with scrambled eggs and smoked salmon. This is such a great way to make the most of your F travel, but make sure you watch the clock as no information is given out about departures, and we had to hike it rather fast onto the train to the plane with only 10 mins to spare before the doors shut. You wil both enjoy the experience so give yourselves 4 hours just to unwind and relax, did not even get around to having a spa or facial, made up for it on the return to LHR. Have a great flight. ^