We took our Drago home when he was nearly 8 weeks (one day before).
In my opion the perfect moment... I wouldn't have taken him when he was younger. Here in Europe the minimum age, for a puppy, to travel without their mum, is 8 weeks.
Our breeder brought Drago to us, from Hungary. Together with his mother and the other 4 brothers and sisters. He said he would get in trouble at the borders if he took the puppy's earlier.
Besides, a puppy needs his brothers and sisters in the first weeks. And he needs his mom too.
Different animal, same story. We took one of our cats home when he was 6 weeks. The breeder wanted to get rid of it. The cat had lots of socializing problems. Now, he is doing fine but I can see lots of differences with our other cat who was taken at 8 weeks.
Six weeks is not dramatically but I hope you can convince your breeder to give the puppy's some more time with their mother!
Good luck with your puppy! We have ours since two weeks now and are very proud owners!