I personally wouldn't get a puppy from a breeder that let their puppies go that early. That being said, if I were somehow faced with this situation, I'd ask myself "Is there something the breeder is giving him that I can't replicate myself?"
If all she is doing is providing exposure to regular household experiences and even-tempered adult dogs then I would take the pup now. After all, I'm in a position to do that myself.
Given that the breeder is irresponsible enough to the pups go early they probably won't be getting any super socialization if they stay with her anyway. I am not a first time puppy owner, have access to lots of even tempered adult dogs both in my home and through work and dog sports. I can create plenty of opportunities for the pup to play with other pups on a regular basis and I can actively socialize the pup to different environments and people. I can give the pup a jumpstart on potty training and facilitate good bite inhibition, frustration tolerance, and impulse control through early training.
If you are set on getting the pup anyway and the breeder isn't doing any of the above, then I would take the pup now and do it yourself. If you can't do the above yourself then I would skip this pup and get a puppy from a truly responsible breeder that keeps the pups until 8 or 9 weeks old at least and does the above.