Yes, I'm sure the temperment makes the biggest difference. But I'm speaking from the experiences I've had with all my dogs at work (dozens of dogs that I've worked with for usually 6 months to 1 year), my friends' dogs, and the dogs I've lived with (mine and roommates' dogs). All were also spayed/neutered. But again, yes, they are broad generalizations, and there are always exceptions.
And it seems like there are enough exceptions listed on this board for me to think the broad generalization overstates the situation. And who knows what goes into that generalization. Females with only other females. Females with males and females. Etc. Family situations, training situations, etc. Raised as a puppy with the other gender, rescued, etc. I think there are enough parameters to keep from knowing cause and effect in gender.
So we all can really just share our experiences . . .