I just added and made it 14...lol. Never saw this thread before.
I know I am small down there so for me its about position if someone is large. Otherwise they hit things that shouldn't be hit at that angle/or that hard. I really did have years of on and off again sex (and a semi-relationship, whatever one defines that as) with a guy the size of an impressive porn star. We were on/off again for over 10 years and...I still remember first seeing um "it" in 2001. Almost fainted. It took alot of practice to figure out how to be comfortable, accomodating, and turned on at the same time. But he has a great personality and we had SO much chemistry, so that helped.
I did say to him that he was going to spoil me for any future "endeavors"...and yeah he did. Sigh.