We have one. The first couple of years were hard work. She is incredibly stubborn and strong willed. Where Labradors work to please you, she expects us to work to please her. She is actually a lot brighter than most Labs I have ever met.
She is great with the kids, but has a high prey drive, so the cat is constantly keeping half an eye on her. She can also be food possessive around other dogs.
She will happily go for long walks and bike rides, but actually is similarly happy with just chilling at home.
I understand what the breeders were trying to say to you - as long as they are well exercised most days, an occasional day of lesser exercise is fine. Mine is happy with a single walk once a day now, but had to be twice daily when younger. She will also not bat an eyelid if there is a (very rare) day when she doesn't get walked, as long as we make up for it the next day. My job is home based though, so she is rarely left for long, and has the opportunity to mooch in and out of the garden as she wishes, which probably helps with the above.
She is petrified of fireworks, gets extremely distressed and destructive, despite all attempts at deconditioning, sedation etc. And this is getting worse as she gets older.
Unlike a lot of Vizsla owners, we do not allow her to be Velcro. She sleeps downstairs in her own bed, not allowed on furniture. And she has always been fine with this. But, if anyone ( at various friends houses) lets her get away with it even once, she takes it as her right to always be allowed on even back home, and we have to retrain her.
Would I have another? Not sure.