Right OP, if you are gaming at 1080p, have no plans to change resolution in the future and don't mind dropping down game settings in order to stay under the 3500 mb VRAM limit, either now for certain games or in the future, then get the 970.
It still is a great performing card for the price.
If you will be increasing your resolution (including planning on going SLI for extra performance to make the most of this increase in resolution) or want to play every single game with max textures and AA then you have three choices:-
1. Buy the cheapest 980 at £419
2. Buy the 290x 4GB or 8GB if you don't mind going Crossfire in the future
3. Sit and wait to see what the next generation cards bring to the table
For comparison I have a 970 with a 4690k and have only encountered issues on certain games when using high details. BF4 with medium/high settings runs fine, COH2 started to stutter once I hit the 3500mb VRAM limit.