I think it all depends on the pup my peeka & boo are 7 weeks and they are doing great! good on potty training and eating. well as for the ears they are just now starting to go up and they are still a little floppy on the ends. You will read a lot on here about when they are teething or have shots or are stressed thier ears will flop and at 6 weeks thier teeth are coming in so i wouldn't worry to much about it. 6 weeks is early to bring them home though they are right about needing to be with momma my babies have to be together or they need my constant attention so if you bring one home that early you need to plan to be by thier side 24-7 because they need someone to comfort them. Besides it's not worth risking the health of the puppy if it won't eat or gets to stressed from leaving it's momma too soon.
Good luck