If you get an 1080p monitor, the 970 is a slightly better option as new games tend to favour newer tech sometimes.
If you get an 1440p monitor, 290x is the better option as it significantly outperforms the 970 due to the better vram and the memory bus.
I would say that neither card is good enough for 1440p (60fps @ max settings) but both are great for 1080p
Just go with your brand preference if you have one

