It has a tendency to brighten the shadows and the scene as a whole. Particularly noticable on Assassin's Creed Shadows (ironically, given the name). In that game it also removes a lot of the fog.

I think that's more an issue with their AI model though and could be fixed in the future with a different model. Some diffusion models have a similar fake brightness / studio lighting issue, e.g. Imagen 4, others don't (Imagen 3).