For me with a middle of the road system,it allowed me to make it 50% prettier,and equally smoother. I have good frames(constant 30-35 ish with an HDD) in black shark with shadows(flat) and high textures for terrian/aircraft,but mostly I'm able to use anti-aliasing which I never could before.Game is smooth with no stutter.To achieve this I had to do 3 important things, 1...delete the shaders, 2...defrag the install folder and finally 3...use the autoexec.cfg with the "no_device_hotplug = true" entry.
If Kate had anything to do with this (and I'm thinking about her Spaghetti code comment)...kisses,and thanks.I Just had to say something.:)