These are the same settings we are playing on our Red Thunder game currently!
It makes infantry act more realistic in battle, expending more ammunition per kill. No more having your men get slaughtered the first second they make contact. In urban environments it makes houses perfect places to hide, your opponent will be unable to see your troops unless they kick in the door: forcing players to check every single house if they want to be sure. No more killing everybody inside a house from 100m away and then knowing the exact second when to stop firing.
I had a team hiding in a house, when the AI walked about 200 soldiers in a massive blob past my men. It took the AI practically touching the window before they spotted my men hiding. It also took the AI a quite a few dozen men to pass my hiding men before they were ever seen.