honestly, while some do not agree with it, I think ANY dog, is a crap shoot.
I've had a couple of rescues, a gsd who had an amazing temperament, but ended up with OCD (knee issue), otherwise healthy, I got her for nothing at 12 weeks of age,,then there is the rescue aussie, a few minor health issues nothing I couldn't deal with, an 'iffy' temperament, tho he's never nailed anyone, he's just a little off kilter in the temperament box
Then I've had a fear biter gsd that I paid a good amount of money for, which was my stupidity at the time, came from a good breeder..I've had gsd's that came from good breeders that were cheap (years ago cheap), and not so cheap, no real earth shattering issues..
I only remember when I was a kid, my parents in charge of our dogs care, they ate crap grocery store food, they roamed the neighborhood, they slept in our beds, never went to the vets, and lived to ripe old ages..
For me , NOW, I pretty much know what I like and want, I know what red flags to look for, I know who I would buy dogs from and who I wouldn't, but in the end, I still don't expect perfection in all areas, price isn't in the equation,