FSX at low FPS behaviour

I hope I am not starting a war with this again, but after months of trying and comparing, and with the first available native FSX sceneries available (EGSS EGPF etc.), I find that: 1) FSX behaves much better at lower FPS than FS9, smoother, no pauses2) The difference between no AI and full AI is much bigger in FS9. In the greater London Area with UK2000 scenery installed, I drop from 40 fps to 15 fps in FS9, but only from 25 to 20 in FSX. Many other examples. 3) Custom scenery (I tested EGSS extensively) also has less impact in relative terms: FS9 EGSS default 35-40, UK2000 14-18. FSX: default 14, uk2000 12 fps. It seems that the overall lower FPS in FSX are not a true representation of its performance. And more important, it may after all be possible to run good aircraft models and sceneries in FSX on weaker computers. Well, some good news there.