Been tweaking settings a bit. Made a lot of the HUD icons smaller in the game menu (down to 50% to try and tidy the screen up a bit).
Also removed DOF from aiming down sight which was annoying me and applied my FOV to ADS (seems to have affected some other bits too like the main map). Need to find your PROFSAVE_profile in My Documents for that - save a backup first, then change the following entries to the values below, CTRL + F to search for them:
GstRender.WeaponDOF 0
GstRender.FieldOfViewScaleADS 1
Guessing there's a lot more beneficial/performance tweaks available in that file, likely all covered in this guys own profile file that you can download from this vid.