But it makes the cliff walls look terrible 
Didnt someone post about this already or am I imagining things?
I tried it earlier in the week or last week and it was ok but not mind blowing as Unreal was when it released using a 3dfx card.

ALT+X and play with the sliders.How do you turn the brightness down? RTX looks good but sometimes tend to think people just think "make it super bright and extra shiny!" Unreal shouldnt be bright and shiny. It should have dark areas, especially like the initial prison escape level.