I have Vista 32-bit on my 2 x 2.0GHz Mac Pro, 3GB RAM, ATI X1900 XT. FSX has never performed well on my computer, so I haven't bothered using it. FS2004 on the other hand used to work great (compared to what I used to deal with), frame rates in the 20s, but since Windows tends to deteriorate inexplicably and irreversibly over time despite not having any spyware or viruses, my framerates at complex airports get down into the lower teens and even high single digits.
I don't know what sort of upgrade would make the biggest difference--buying the new 8800GT, changing Windows to 64-bit and/or getting even more RAM. To say the least it really bothers me how Windows just slows down over time like a train slowly derailing.
With regard to the X-Plane vs. FS discussion, I much prefer FS because of the airports with actual details (and other such more realistic elements) and much easier-to-use interface. However, I must say that X-Plane's physics are more realistic than those in FS.
I don't know what sort of upgrade would make the biggest difference--buying the new 8800GT, changing Windows to 64-bit and/or getting even more RAM. To say the least it really bothers me how Windows just slows down over time like a train slowly derailing.
With regard to the X-Plane vs. FS discussion, I much prefer FS because of the airports with actual details (and other such more realistic elements) and much easier-to-use interface. However, I must say that X-Plane's physics are more realistic than those in FS.