Here's a definite answer to whether size matters: YES. But it's not the affirmative size you're thinking of. According to the women below, there can be an issue with an overly huge phallus, please, please, please go easy on it (no pun intended).
#2 IT’S BLOODY HUGE
Photo: Pablo Alfieri
“One night I went home with this guy I’d met. We basically stumbled into his place, not even bothering to turn a light on anywhere. I get a glimpse of his cock in the light of a lamppost outside and it’s huge… Just long and thick and ridiculous. My drunk self decides I can take this and I’m so drunk and so horny that we get to it and he goes in dry. Hurts at first and then I’m getting wetter and wetter and it’s crazy. Anyway, everything reaches its conclusion and he gets up to go for the inevitable post coital piss. On his way out he flicks on the light. There is blood everywhere. Between him splitting me open and the lack of foreplay his bed has turned into that hallway from The Shining. And I’m so drunk and embarrassed I throw on my clothes and thirty seconds later I’m running out of his house barefoot with blood down my legs.
Was good sex though.”
— boneratheon, Redditor