Older DX sims never look quite as good in W10 for mine, ie: GPL, Nascar2003, GTL, GTR etc.
I had tested extensively with and without NV inspector settings and was never satisfied.
Why I do don't know but I believe it had to do with changes to the DX core and the way it handled quality settings.
I remember engineers at the time saying how some older titles would be adversely affected.
I get no net gain running rFactor2 on W10 only inconsistency in my older sims.
I am NOT saying that is everyone's experience.
Even still it is not just AV, imho it is all the other automated garbage and process W10 runs you need to look at too.