After getting to know probably over 100 vizslas working for a breeder for 2 years, I'd say there really is no difference between the sexes. It's really up to your preference.
I believe females are easier, because they aren't so focused on reproducing. I hate walking a male dog that has to stop and pee on every tree. They can also get distracted on the hunt if there is a female dog in the area.
Females, however, will cost you more because of the spay. If you choose not to spay, then you have to worry about pyometra, which is a nasty uterine infection that many females will develop over time. I work at a vet office and we probably see 3-4 dogs a month with this condition. the only cure is to spay the dog. If it's not caught in time, then it will kill the dog.
As far as velcro-ness and hunting ability, that's really up to the genetics behind the dog and not so much the gender. Good luck in your puppy search.
