Kacie my coatie is not the sweetest laid back GSD. I don't know her pedigree but think she's a mix of SL/and WL's.
She can be reactive to other dogs and people, but with my family and our other dogs she is pretty docile and sweet. She is fairly active and would be more if she didn't have a bum elbow. Of all my GSD's she is the lowest as far as energy level. Not much in the way of ball drive or food drive, but her prey drive is big.
I don't really think her coat type has much if anything to do with personality or temperament.