To me, it seems like more liability, as a bigger dog is stronger and potentially harder to control, not to mention more health issues with hips/joints.
I prefer the over sized GSD & always have, Specifically, I like 'em tall, even very
tall, lean & athletic. *shrug*That's just me. I found a GSD breeder who consistently produces what I'm looking for...healthy, sound, long lived, INTELLIGENT, discerning & of impeccable character. While I wouldn't use, or recommend, her GSD for competitive agility, they have an extremely low incidence of hd. This isn't really surprising. Many large, & even giant breeds, are noted for low hd scores, ie Irish Wolfhounds, Anatolian Shepherds, Scottish Deerhounds, Akbash dogs etc. Size alone is no predictor of orthopedic soundness.
HARDER TO CONTROL?????? Puh-leeez. I'm nearing sr citizen discounts with bad knees, lousy hips, poor balance & near total body arthritis which is advancing rapidly. IF physical strength was the source of my *control* I'd have been puppy chow more than a decade past. Meaningful control is mental. In a purely physical contest, most of us would be toast at the paws & jaws of even a smallish, poorly conditioned GSD. My control of my dogs is largely rooted in a deep seated desire to please me & get my approval, NOT physical strength or raw power. IF you require physical power to 'control' a dog you'd better look at Chihuahuas or mebbe gerbils.