I've never seen a GSD/lab but he looks like he has quite a bit of GSD in him. Do some research on temperment of both breeds and you're most likely going to get a mix of the two. I think its hard to tell what kind of personality you're going to get with a mix breed. But on the plus side they usually seem to be healthier (or free of more genetic/breed issues)
He is a very well behaved dog, and very cute, I just am a bit worried is all. Freaking out a bit! As I said, I've wanted a GSD for years. I really want those erect ears and long snout. The regal Shepherd shape.