Yes, FSX is a whole new thing. It also needs better system specs, but myself, I can run it at about 18-25 FPS (And that's because I locked it at 25 FPS) with both Scenery and Autogen on "Dense" (Tried Autogen on Very Dense, that was ok as well, but some lower frames, so I turned it down in case I was gonna fly in big cities) and the mesh and other things on full.
And as you questioned, FS2004 DOES work with Windows Vista. I used it for about a month before I got my FSX working.
And did I mention this was a laptop? Can't believe all the stuff I heard about FSX not being usable on laptops when I can play it on three times better graphics and just the same frames as my old computer with everything on Minimal. My old one was a desktop too.
