I've got "Ultimate Terrain USA" for my FSX, and "Ultimate Terrain USA and Canada" for my FS 4004.
And the FS 2004 version works wonders for me. (Much better than my FSX version!).
Together with a suitable "Mesh" for the area covered, it is one of the best scenery add-ons for me. Brings the whole area to life (accurate!)!
Paul....FS 2004...(and FSX)...

...!
Note: the FSX version of UT conflicts with the default road system layout, when "Road Traffic" is enabled"