You know I love both sims, but over that last week I have been up dateing my fs2004 to a newer more up to date installation with new scenery up dates and night textures and now toaday I just bought the new Water up grade for fs2004.
The addons I used were the following:
Ground Environment Pro
Zinertek - Ultimate Night Environment Professional
Zinertek - Ultimate Water Advanced (FS9 Only)
And I picked up a few new planes along the way to keep me interested.
I have to say that very soon, it will be hard to say what one is better. Fs2004 with all the right mods performs faster looks as good and you can build Fs2004 supported with unbelievable quality in the mods, whether aircraft or scenery. It comes down to preferances now. Soon some one will build new moduals for fs2004 that will alow animal herd movement and all of the other new dynamic stuff the new engine in fsx can produce.
Its just a matter of time. With the majority of flight simers still in fs2004 with no inkling to move over to fsx. no activation makes it more appealing as well. I think fs2004 will be here forever.. it seems to be gaining steam more now then ever.
Here is a nice shot of my Capysim 707 over my new water installation!