The slogan is a pun: the first meaning is that you can't have a better experience as a passenger than on Pan Am (debatable); and that no airline can beat Pan Am's experience (ie all those flight hours, pioneers, flying boats, Clipper Skippers, you know the words...). The second was definitely true, but the service on board went downhill within a few years of the 747s arriving, as the airline became stagnant, no new hires so the staff (especially in the cabins) became older and more jaded. Things actually started to get better towards the end, with Thomas Plaskett at the helm. If it hadn't been for the Gulf War, Pan Am might have survived, albeit in a reduced form like TWA but with some of it's trans-Atlantic routes intact.
I know it seems silly but I feel really sad that Pan Am is gone, they were, for all their myriad faults, the definitive airline and the blue meatball was the most potent symbol of commercial aviation ever. The launch customer for the 707 (-120 and -320) and the 747, for god's sake. If they were still around I would gladly abandon my musical career to work for them. All I have now are the luggage tags (and, as mentioned elsewhere, my haul of goodies from the Pan Am Aware store in Miami Springs).
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz