Sorry for the OT post, mods 
My settings are as follows:
IN GAME
Resolution: 1280x720 (The native res is 1600x900)
Full Screen: Pseudo
Model Detail: High
Building Detail: High
Land Detail: Medium
Forest: Low
Visual Effects: Medium
Texture Quality: High
Anti Aliasing: Off
Anti Epilepsy: Off
SSAO: Off
Vsync: Off
Damage Decals: High
Building Amount: Medium
Land Shading: Low/Medium
(Low in ACG server, Medium in ATAG. - This is due to ACG having far more clouds than ATAG so I play a bit of a balancing act with the settings to maintain FPS)
Grass: On
Shadows: Off
Roads: On
CATALYST CONTROL CENTER
Running: 12.4
Anti Aliasing: Use Application Settings and Morphological Filtering both ticked (For some reason this gives me an extra 10 fps)
Anisotropic Filtering: Use Application Settings
Tesselation: AMD Optimized
Catalyst AI: Performance
(Enable Surface Format Optimization ticked.)
Mipmap Detail Level: High Performance
Wait for Vertical Refresh: Off, unless application specifies
Anti-Aliasing Mode: Multi-sample AA
Open GL Settings: Triple Buffering unticked.
On Repka servers I get fps around 58-62
On ACG I get around 36 to 22 (Depends where the clouds are. lol)
On ATAG I get an average of 56
Single Player missions? Practically unplayable the minute the "bad guys" turn up. I will add that that is only with the stock missions, mind. Missions made by the fanbase seem to run like clockwork regardless of clouds, amount of planes in the air etc... this has led me to believe that the Development team are the victims of a powerful and ancient curse.
Hope these are helpful and work for you too! Happy hunting!
PS: If anyone reads this and has any further tweaks for me that will improve performance without lowering the eye-candy, please share!