It depends on what games you find yourself wanting to play and whether you'll tolerate slightly lower resolutions towards the end of a 4 year cycle or not.
I only upgrade my GPU when a 'killer app' game comes along. Otherwise I make do with what I have and use a little scepticism towards heavily hyped games that actually turn out to be quite good but not legendary (My opinion on Watch Dogs...) and just choose to run them at slightly less than max settings.
I lean towards x80 cards also because I end up with less old graphics cards lying around wondering about what to do with them. Heheh.