A few thoughts.
System requirements:
I've got a fairly buff system - 2 GIG RAM, AMD X2 4400, and 2 Nvidia 7900 GTX's.
I couldn't break past 12 frames per second and that was with the FPS slider put up to 90. This thing choked my box like nothing I have seen - holy bloat - fix that ****.
Dynamic scenery:
All nice and good, but if you turn yr sliders up to see motorboats and hang gliders, kiss yr frame rate good bye.
Terrain resolutions:
The good part, is it looks like MS got the point that the 3 meter texture res wasn't gonna cut it with the new high res sceneries comming through the pipe in 2004. So they upped the resolution to as high as 7cm per pixle. Not a bad thought, but 2 years late in the timing.