I was actually talking to my grandfather the other day about this very issue. He was back in his day a regular Concorde Flyer(Y at F prices and my grandmother used to say) and flew what would be the equivalent of two AONE5's/year, so spending in the at least 50K/year 25 years ago which was not a small sum and fully self funded. Anyway he would never fly anything but F and only last year did he fly F after 20 years to visit the great grandchildren on SQ unfortunatley he wont extend that to me until I'm flying with a kid. But he said F had increased exponentially compared to the rest of the cabin, back in his day they did not have lie flat beds and the most you could look forward to was being welcomed aboard by name and enjoying a seat that was almost like a bed.