FSX or FS2004

Hi Guys,

Just wondering about installing fsx when i get my new computer , or re-install fs2004. The computer i am getting is of pretty good spec : 3.2ghz cpu, 8gb ddr2 ati4890 1gb graphics card, not to sure about motherboard spec but its going to be good aswell !
i am getting mixed reviews about fsx, but the million dollar question is : is it better than fs2004. i am really looking to get my fps smooth as they get while still using top of the range add on sceneries!

is there anyone who can make that executive desicion for me , or point me in the right direction

cheers

James Stott