Doha is for me one of the best three airports in the world.
As Gold for life you should even have time to visit the Business Lounge (assuming you are not in QR Business - see the lounge threads here for more details) which is technically one of the 'less good' lounges, but still miles ahead of what you would experience from any BA lounge at LHR (apart the CCR) and fairly similar to a FLL lounge.