Cit try these settings in video8 file
0.3,LOD
0.3,ObjSize
Or just set the sliders both under the L in detail. Not quite max but it will get you 50fps.
Your in danger of starting to rant Cit because you cant run it as fast as you want at full settings, however it seems apparent that the Radeons are definitely not up to speed with AH2, hell even GF4 TI4200 seems to be nearly on par with 9800 Rads.
I agree the terrain is very dark and as somebody already mentioned looks like a heavily overcast day, but without the cloud cover.
As for the current FM i cant see the problem keeping in mind its still beta.