Two completely different dogs and hunting styles. I've owned GSP's and English Pointers for over 50 years. My upland style of hunting of hunting is to use a wide and long ranging GSP that covers a lot of ground very fast and doesn't miss birds. Labs are more laid back (IMO) with a slower more methodical style. I have buddies that have great waterfowl labs, especially in really cold weather. I'm thinking if you are a lab guy, you might not like a GSP, you should try hunting over one at a preserve to see how you like it. GSP's were bred from 16 different breeds of dogs including bloodhounds, that's why they have such good noses. I'm partial to GSP's.
One buddy of mine used his English Pointer to find and point birds and then he sends the lab in to flush and retrieve the birds, it works pretty well.
