mtaylor: I have a macbook pro almost identical to your laptop in terms of processor, GPU and ram.

I am using the 11.5b ATI hotfix drivers and patch 1.1 on windows 7 pro 64-bit

Here are my settings:

Screen Resolution 1440x900 Fullscreen

Texture Downscaling: None
Texture Memory Size: Medium
Shadow Quality: High
Number of Shadowed Lights: High
LOD Distance: Near
Bloom: Enabled
Light Shafts: Enabled
Anti-ailiasing: Disabled
Blur Effects: Enabled
Depth of Field - Gameplay: Enabled
Vignette: Enabled
Wet Surfaces Rain Effect: Enabled
SSAO: Enabled
Motion Blur: Enabled
Cinematic Depth of Field: Disabled
Depth of Field - Cutscenes: Enabled
Dangling Objects Limit: Disabled
UberSampling: Disabled
Vertical Sync: Enabled
Decals: High Spec

Game is responsive although it will drop frames occasionally, probably because of caching on my slow hard-drive. I can't prove that it helps, but I did the following in the command window to increase the memory usage of NTFS:

fsutil behavior set memoryusage 2

and I disabled Aero when launching the game by doing this:
right click launcher shortcut -> Compatibility tab -> Disable Desktop Composition -> Apply

To answer your questions though, I've found that decreasing the resolution allows the game to run smoother with more stuff turned on and running it at 1920x1200 on low spec even seems to run slow for me. I'm not sure how to check the fps, so no real ability to tell you real numbers.

hanns.g: Glad you are happy, Charles. :)

Taylor, you can get a free version of Fraps if you ever curious or frustrated with frame rate.