I'm sure there is variation in thickness from person to person, even hair to hair obviously. I would also say prep has something to do with it as well. I like to shave after a shower. I get steam and hot water to soften hair. Hair will hydrate to an extent. You also want your prep and whatever soap you use to be a good lubricant. you don't want a blade skipping.

IMO, the sharper the better. Just find what works for you.