Hi all.I'm currently running FSX SP2 on XP PRO SP2 (32 bit)My rig is a Q6600 (3GHz) 4GB mem, 2 x WD raptor 10Krpm, 8800 GTX.At present I've applied all the Nick's best tweaks (3GB switch included) and I'm happy with the global performance of my system.I would like to try XP pro 64 bit but I would like to hear something from people who are using it (improvements, issues...)Thanks in advance Fulvio

Other than general incompatibility with some programs, but general compatibility with many other, no real performance increase in FS, and native support for more than 2GB, nothing really.Used it for some time.