Fix Mouse Smoothing and Aiming
Fix Mouse Smoothing
Go to %USERPROFILE%\Documents\My Games\Borderlands Game of the Year\WillowGame\Config
Open WillowInput.ini.
Change bEnableMouseSmoothing=true to bEnableMouseSmoothing=false
Fix Mouse Aiming
Go to the configuration files location (mentioned above).
Open WillowInput.ini.
Change LookUpScale=-250 to LookUpScale=-300
Open WillowEngine.ini.
Change OneFrameThreadLag=true to OneFrameThreadLag=false
Notes
Feel free to adjust the mouse sensitivity as needed. This can be done with the in-game slider or by changing MouseSensitivity=100.0 (WillowInput.ini) to your desired value
Setting OneFrameThreadLag to False may cause a drop in performance.