I scaled down my characters to real human measurements (around 1 m 70 cm), in meters units. I found it harder to manipulate because the characters are tiny in relation to the scene.
Also the skin shader seems to works differently. The smaller the size, the higher the strength the sub scattering is for my skin shader. I don’t understand why, it causes the facial features to lose in definition.
Then the scaling down seems to make the head and hair shrink too in viewport rendering (not so sure and not as concerned about this, but curious)