The few Vizslas I have met have been fine dogs. But I have met more good GSPs, just more out there. Had two GSPs ourselves, a male and a female. Male would range out much farther in the field unless you were firm on pulling him up short. On a leash he was just fine, not a puller or anything. The female naturally ranged forward at perfect shotgunning distance. Both terrific with the family--to include two infants--the female even protected our daughter once (male was deceased at that point, or the illegal would have bled even more). Also took the female GSP hog hunting. Not as a bay or catch dog, but just a dog to keep my daughter company. Female GSP was really old at the time, but had a wonderful time walking the fields and sitting with my daughter in a blind.
FIL had a couple more. He did not hunt them.
All the dogs were from families who bred a couple successful local hunting GSPs. All were good, healthy dogs, though I don't know how my FIL's would have done in the field.