OK so a quick update...
Just finished a session on ATAG and credited with 3 kills... a first for me in a very long time. I'm using FXAA Les Neutral6 settings and "Game" preset mode on my monitor. I'm fairly positive that with these settings - plus the earlier advice with respect to Steam Cloud, it is easier to spot the enemy at a a distance. Time will tell of course - but thanks to all contributors I think my enjoyment of the game has just stepped up a few levels. Cheers!