Hi and welcome. As others have mentioned I own both. Two males V's and a female GSP. My GSP was a rescue also. But, from the history we can gather, she was bred specifically for hunting and was bred rather small for a GSP. SO potentially her workings might be slightly different. But, I will share what I see as the differences from what i have seen in mine and also from friends with other GSP's.
To me, there are more similarities than there are differences between the two. Taking out personalities, as all three are very different and also perhaps removing some of the instinct comments as the boys are much younger than the pointer is.
My GSP will tend to want to range a lot further in front when out bush walking, or walking a field of birds. She is however, much easier to control once on point.
My V's will be a lot closer and tend to listen more to me when finding the birds, but then once on point, control is harder.
Once again, I think a little of this is the age of the boys, Astro is only just a year and Ozkar is 16 months. So they will develop further as they mature and I havn't really put a lot of time into getting them steady.
I might also point out that I am not a trained hunter as such and neither have the dogs been. It's just what they and I have worked out together almost naturally.
All three are totally bird focussed. The mere mention of the word has all three of them doing circles to try to find them. So prey drive is very strong in both from what I see.
Being a female, my GSP is both a little more stubborn at times, but also way more compliant at times too, if that makes sense. It just depends on if she has her game face on or not.
The V's and the GSP both are about as soft as each other in terms of command sensitivity. Either will get snakey with me if I am too harsh with the words.
The pointer is probably the stronger and more reliable retriever, but i attribute that more to her additional maturity than anything else. She wasn't as reliable when I first got her.
She is also a more high energy dog than the V's are, but once again, this has really only become evident recently, as she reaches towards 2 years old. 6 months ago, she was a little less highly wired. The boys may get to and perhaps surpass her energy level going on the increases I have seen recently. But only time will tell for sure.
Intelligence wise, I think the Vizsla has a marginally more switched on mind. Zsa Zsa can miss the point some times when training. It can take a little longer to get it through to her, where as, the boys catch on very quickly. Not a large difference though and sometimes the boys are too smart for there own good.
Either way you go I think for a hunting dog, when choosing between the two breeds, it's more a case of which dog has it in between their ears and which doesn't, more than a GSP or V thing, if that makes sense??
The only other additional advantage............. Vizslas are chick magnets!