I have 35% all around and 70% on my windshield. I wish I had done 20% all around and 50% on the windshield like my RAV4, mostly because the windshield is big enough to still let in a lot of light.
I felt the ceramic tint does help, especially reducing skin heat while driving (as mentioned) and some radiant heat from the black dash, but indeed physical shades do work much better. Installing a semi-permanent roof shade on my center panel saved me about 50wh/mile in mid-summer cooling (95-105 degrees).
**I believe the center roof panel is already ceramic coated so I don’t know if more tiny film will do much. The main issue is that the glass itself gets physically hot from absorbing light, and therefore the glass itself is what is radiating heat down into the cabin. More tint doesn’t change this, but an opaque roof shade with a small air gap makes a huge difference.