Ok the GTX 970 4GB runs the game much better than the unlocked overclocked 6950 2GB. Might be memory capacity related but who knows. On the 970, at 2560x1440 Balanced preset, I see 2.1 GB VRAM used and it runs 60fps with vsync. Putting the game on maximum quality is too much for the 970. Looks like 20fps. There are some additional effects that must be extremely demanding.
If you can run the game well, it's worth trying. It's definitely got the gameplay I think.