I use the radeon 5870 and haven't had a single issue with them what so ever. I run FSX on max settings at 1920x1080. Over aerosoft manhattan x in pmdg 747x VC about 20-35 FPS and no stutters, veerrry smooth! The only reason I run 2 is for my 3 monitors, not that 2 cards makes a difference in FSX. I would also recommend the 5870

The 5870 is a great card, but due to mip-map undersampling (which is built into the Catalyst driver), it produces lesser visual quality than NV cards do, at least for MSFS. If it works fine for you that's great, but most here prefer the image quality produced by NV cards.

Not to be close-minded, but when I do upgrade it will for sure be an nVidea based card - for several reasons, but mostly because it's what almost everyone running FSX is using. When ATI cards are running WAAAAAYYYY better than nVidea (specifically for FSX, not Crysis or whatever other benchmark game), than maybe I'll take a look. But for now, everybody running ATI is claiming it works "fine," which means it's not really any better and therefore not worth the risk when so many others claim they had problems with ATI.

I agree completely. If my sslystem was dedicated for FSX only, I would have gotten the GTX285, however, because I play other games such as Cod 4, Cod:MW2, and many other games, the 2 ATI runs better for me.