That's honestly a tough question to answer. The Saint and the Flow, like many of Latitude's discs, are completely different discs between plastics and weights. A 166g flat GL versus a max weight domey Opto might as well have different names on them. Although, I think these differences become less pronounced as the disc speed goes down. Bolts and Havocs can see some pretty drastic ranges in stability.
The short answer is yes, the Saint can fly similar to a Flow. I actually stopped using my Flow for now because the Saint showed me I could get the same distance with less effort. But all the means is I don't throw far enough to maximize the Flow's potential. If you throw over 400', I don't think the Saint will offer you anything the Flow can't in terms of distance. If you're a 320' thrower like me, then it will be about telling us what kind of Flow you have so you can get some pointers on what types of Saint might work best for you.