only some models have a lifetime warranty I think just the AR ones, and those are 570's. 7850 is newer and have will have more matured drivers, plus overclocking is better, almost half the totla wattage of a 560 ti at 135 Watts only. Physx is actually quite useless, and even if you needed it, you can buy a cheap one with like 20 CUDA cores i think. CUDA is not really necessary unless you're sure you know what it helps for. If you only know that it's good for programming, then it's useless to you.