I beg to differ Gsync is about making a fluid gaming experience when large drops in frame rates occur. This is most likely to happen at 4k resolution when most cards can't even manage 60fps in the first place.
So gsync is an ideal technology for 4k monitors. Read the gsync reviews and they tell you it starts to work really well at sub 60fps.
This.
Gibbo trying to run 4k at 25FPS will look crap on any monitor, however if you have a monitor and game that is running 30-50FPS up and down all the time then G-Sync will help a lot, it will not make constant low FPS look better as other peep stated 4k will be for most.
4k is tomorrow not today, 1440p should be the new 1080p.