Labs can have problems with their cruciate ligaments, as well as the other hip/elbow problems, and buying a mix breed like that often means you can get a mix of breed-specific problems. That said, a lot of those problems can be avoided/minimised by keeping the dog lean and not over-exercising (especially on hard ground) at a young age.
I don't have much experience with pointers, but AFAIK most gun dogs (pointers, vizsla, weimaraner etc) are fairly similar in requirements; probably the main one being exercise. If you're willing to make the commitment to keep them busy (not necessarily hunting, but regular big walks off-leash) then they are amazing dogs. I may be slightly biased given that we have a 2 year old vizsla, she's an amazing dog but pretty intense at times both with energy level and attention needed (they call them velcro dogs for a reason!).
Any dog is a big commitment, especially a larger breed like a lab or a pointer that will need plenty of exercise. Labs also are well known for being gluttons, so keeping their weight in check can be a challenge. As well as the viz we have a beagle/fox terrier cross and he's a pretty good mix, I'd say go for the purebreed even if you aren't going to hunt/show/breed as you're more likely to be able to get a good idea of what you're in for, but don't completely write off the mutts either...