Noise issue and OptiX denoiser

I made this with CC & HDR Light Studio:

It is not ready, as you can see…

My settings were 512 samples in Path Tracing, no motion blur and:

I tried to solve the firefly issue with OptiX denoiser:

It works, but I feel that Optix denoiser takes also away some crispiness from the render.

Do I have any settings to change to find a better balance when fighting the fireflies? I know they are coming from the reflective floor surface, since in the first cc & HDR Light Studio render I did not had this problem: Beutiful skin with CC character & HDR Light Studio