Girth preference varies from woman to woman because some are tighter and some are looser......
But length? No woman can actually take all 12 inches because 3 to 4 inches is gonna be outside her puzzy. The visual stimulation might be important for some of em, but logistically it doesn't work. Like trying to put an elephant into a Miata.
A typical cable remote is about the max an average woman can take where she can get it all up in there. Everything else is just extra for showing off. If she's really horny or has extra cargo space, she might be able to handle more.
Girth also has limits because if you're TOO blessed, she not gon be able to give you good dome. Like a broad tryna suck a fire hydrant. All teeth.