in some specific conditions the 290x can go as far as matching the 980, but overall the 970 and 290x are pretty close, the 970 is clearly faster for some gameworks titles, and can use a lot less power (like close to 100W in some cases), you are not paying for it, but someone is and there is the bonus of a little bit less heat in your room/case...
I would personally chose the 970 because of the power advantage, and potential for better DX12 support, and the Nvidia advantages (like gameworks), but the 290x looks like a better deal in terms of price/FPS, it's just that it's not a very big advantage in this case I think.