Talking about penis size, I suspect average is best. More versitile.
There is such a thing as too big. I am not big, but I am told that I am a bit bigger than normal, both thickness and length. I always thought all the girls saying you are so big was just stroking my ego, but recently I saw this asian spinner who is extremely tight. She said mine was the biggest she had ever had and she literaly could not get it in without lots of lube and even then, she grimaced uncomfortably on entry I could see real pain and uncomfort. The the sex had to be cut short as it was too painful, apparently my penis would hit the back of her wall. I have seen her since as we get along well. She says she said she was too sore for sex and had to take the next day off after seeing me. And even now initial entry can only be done with lube and lazydoggy so I can go in slowly and I do not go in too deep. She said she never experienced that with others but I suspect she saw mostly asians in the past. With other girls, again mostly aisan spinners, my preference, I get a mix of compliments and complaints, nice to look at but some working sp, gets tired/sore/worn out faster
However based on my experiences, those that are bigger than me will probalby have limitations with some of the girls.