It seems pointless to think about the amount of energy in one molecule of palmitic acid compared to one molecule of glucose, and then conclude that beta oxidation produces more energy. Unless you measure your food intake in moles of glucose or fat that is. But this difference is the reason why fat is more calorie dense, so if you eat the same number of calories of glucose and fat I wouldn't expect a significant difference in energy production. Here, on the other hand, there would be a difference in CO2 production, due to the decarboxylation of pyruvate, so i think this is why burning glucose would be preferred.