Well, I was a long time FS2004 flyer who finally bought a new PC (see specs below).

I decided to buy the FSX Gold edition and see what was new!

I was expecting to be disappointed and to uninstall and go back to FS2004, but I was pleasantly surprised!  

Out of the box the sim ran quiet well with reasonable sliders.  Visually, the default FSX environment was much improved over FS9 + a bunch of texture and other add-ons.  

Everything overall feels much smoother than FS9.  I had to turn down AI traffic to almost nothing however, but AI traffic killed my performance in FS9 as well. 

Seeing moving cars on the roads and other ground traffic is amazing!  

I've had to add a few scenery and other add-ons since I got started:

Active Sky Advanced (I already had this for FS9)

Ultimate Terrain X (Usa and Canada)

Ground Environment X

Flight Environment X

Plus, I'm downloading FS Genesis mesh at this very moment

FSX is not without performance problems however.  Adding even moderately complex scenery or aircraft can make framerates plummet.  I've been trying to stick with simpler GA addons (which I prefer to fly anyway).  

Thanks for reading, I hope to have a few FSX screenshots ready soon.  

Intel Core 2 Quad Q9650 3.0 ghz
4gb RAM
Vista 64 bit (soon to be Win7)
Nvidia GTX 275 896mb