As long as there is enough cock to fill me all the way up, I'm totally happy with it. That would include 90% of them. If it's not big enough to hit the top, shall I say, I could wish for more, but so what? There's so much else we can do.
If it's very long and skinny, it can be a bit "pokey", and it's owner should be careful with it. (VERY few fall into this category, so don't worry).
If it's humongous, two problems might occur. First, the guy might be not realize he can hurt someone with that thing and be overly enthusiastic. Secondly, he might be aware of the fact that he can hurt someone and be too gentle (much more common), even when I ask for more.
It seems like it wouldn't be the greatest thing to have a huge cock that you can never sink all the way into a woman.
Many guys who have great cocks consider themselves to be on the small side when they are not because they compare themselves to porn cocks.
Some of you guys might be surprised to learn that many guys aren't that interested in pleasing the woman. If you are, it SHOWS and we appreciate you, regardless of the size of the cock. This is so much more important, really.