Been having a look at the 290x etc and thinking about a return.
But for me the killer feature is the Nvidia software as much as the hardware. For example Game works is a massive apeal to me as well asadaptive vsync.
More VRAM is more important than game works imo. Though it depends how long you plan to keep the card for.
I really despise technologies such as Gameworks - imagine NVIDIA have their way and it finds itself in every triple A game released - it would effectively remove AMD from the GPU industry, leaving NVIDIA as the sole provider.
Imagine prices of new GPU's if that were to happen. We'd also get 5% increases per generation, just as Intel can get away with now, since they have no competition CPU wise.