I've never measured a dick, but my guess is that most men I've fucked were average pertaining to dick size. I'm plenty happy with average.
I've had a few partners with larger than average dicks and I didn't like them for two reasons: they hurt me inside and I can't give proper oral to a big dick.
The good thing about big dicks is just to do some positions that are more complicated with average/smaller dicks. But since I love giving oral and need that to be happy, I prefer average dicks.
It's very nice to feel a nice stretch inside, but only tiny dicks can't give me that sensation. A vagina is very, very snug.
Another thing is muscles. Once I've played a video game with my vagina at a clinic, clenching a thing inside to move a moving line on the computer screen, avoiding obstacles. In the name of science. The doctor told me I had the strongest and with most control muscles he had ever tested.
Pity it isn't an Olympic sport.