Hi,i fly the FS9 only. I have a big system (i7 920 @ 3.5ghz, ASUS P6T, 12gb 1666mhz ram, EVGA GTX260, 1000w power supply and 1.5 TB space) but the FSX (with some addons) is at about 15-20 fps at all... that sucks. Unflyable for me. :( I think the FS9 is much better then the FSX because, it is very framefrindly also with REX and PMDG