I had a conversation with my wife about this a few days ago. We're introducing ourselves to the world of swinging and the last couple we had sex with was a really good match for her. She had so much fun and he was all over her. He fucked her furiously and she enjoyed it very much. So when we evaluated this later (yes we do that every time), she told me how that worked, because I was wondering why it was something we rarely do (that hard I mean).
Her idea was that it had to do with the length of his cock, while we were very similar in girth, his was quite a bit shorter than mine. Every time I go ballistic on her like that she hurts or even bleeds. With him, that just wasn't the case because he didn't hit that deep.
It's double feelings for me, because I like fucking her hard and deep, but I don't want to hurt her. So yes, size does matter, also in this perspective and a long penis is not always better depending on who your sex partner is