My girl most definitely prefers any four legged over the two legged variety. Sure, she gets excited when someone comes home or visits. If you would play fetch with her, she'd do it forever. If you run with her, she will choose you over the new dog in sight after a brief moment of hesitation. However, on any normal given day, she'd choose to meet a new dog/cat/bird/squirrel over any human. Okay, the birds and squirrels might be for food but the dogs and cats are for play.
I got her at 4.5 months. At the time, she was not the last of the litter to leave home. When I was there to meet/buy her, she was so preoccupied playing with her brother and mother, she barely had the patience to tolerate us humans handling her, keeping her from her playmates. I think the breeder had also been busier than usual with her life at that point during the developmental stages of my girl's life to have given her as much human attention as she should otherwise have done. Besides my girl's immediate biological family, she also had other dogs to play with. Once I brought her home, she was immediately attracted to my cat. Once the cat accepted her, she'd report to the cat on call 100% of the time--she would drop all that she was doing to run to the cat. We've never taught her the cat's name purposefully, but that was the first word she has learned from us and responded to without fail.
The only odd thing is, during her puppy classes, she did not care to truly play with any of the other dogs. There were three others: a shih tzu, collie border-cross lab, and a smaller yorkie. When she would excitedly approach the very friendly and gentle giant of a collie-mix, she'd suddenly start cowering and trying to run from it when it approaches her to nudge her for play. She'd sometimes go over to check out the yorkie boy, but she'd lose interest and was more there to take a bite out of his treats than to socialize with him. But immediately afterwards, she'd show a lot more interest in the new dogs coming into the store and also outside during her walks. She'd want to do the pounce and play with them.