Usually you would say yes it's cheaper and possibly cheaper, but Nvidia Drivers are a lot more reliable than the AMD ones we already know that the stock R290 was rushed into production with the effect that they were increadibly noisy and hot an aftermarket R290 would be a better bet but just read the forums and you will see that many people have problems with running particular versions of AMD Drivers. For me I want a card I can stick in the PC and have no problems.
As I mentioned benchmarking and overclocking is a completely different kettle of fish but as you mentioned it's mainly for gaming then Nvidia would tip the balance for me.
As I mentioned benchmarking and overclocking is a completely different kettle of fish but as you mentioned it's mainly for gaming then Nvidia would tip the balance for me.