We have a german shepard x lab. We got him when Kane was 4 months old, so they have grown up together. At first Zeek was very playful and got excited very easily.Typical puppy stuff. But we have found that since we had him snipped he is a different dog. Zeek is a great guard dog too, which is a bonus!
he is very gentle with Kane. Kane Sits on him and puts his arms around his neck in a big cuddle and Zeek does nothing. Even when Kane is being rough(pulling tail, lips etc), he will not do anything. If kane has one of Zeeks toys they play a gentle game of tug of war, Zeek will always take it on to the grass, so If Kane falls he wont get hurt. The worst he has done is got a bit excited and knocked Kane over.
Zeek is a great dog, but unfortunatly does have some of the lab dopeyness some days. Would Highly recommend either of these breeds. I grew up with German Shepards and they were very placid, but like all big dogs they need regular walks and lots of room to move.
Good luck with your decision.