I was with a woman who had a huge ex (estimated 9x7- about the same size as her big dildo) but this had been many years earlier. She'd met another guy who was even thicker but hadn't fucked him as his own foreskin was too painful too pull over his massive head. She was a real size queen and very turned on by big cocks. That said, she likes being fucked hard, something she reckons she could never do with mr 9x7, she also reckons that at times he had trouble getting it up, even though he was only 21 when they split, though to be fair to the guy, he was close to 3x the volume of the average cock...
She told me my cock (which she regards as average) was great but girlfriends are prone to doing that. More significantly, she fucked me several times as a fuckbuddy since we split and then settled down with a guy "like you but thinner", his lack of girth apparently being an advantage as she's enjoying anal again (I was always "too thick" the few times we tried).
My point is that even a self confessed size queen ( this woman was hoping for 10"+ last time she was online dating) might not associate good sex with those big cocks. She's even less likely to use it as a criteria for a long term relationship. My ex and Mr 'thin enough for anal' have just had a baby together.