What differnce will I notice?

I know a GTX 660 or R9 270x can run Battlefield 4 at ultra settings effectively.. Also, all the cards from and above GTX 760 (also above R9 270X) can run BF4 too.. But what will be the difference I'll notice for the same game?
 
Solution
You will get higher fps, which leads to smoother gameplay. You will need at least the GTX 780 to get an average over 60fps on ultra @ 1080p.

lewisdc

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Mar 31, 2014
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I am using a Zotac GeForce GTX 770 AMP! 2GB ( My build is shown in my quote in the bottom right) I am running Battlefield 4 (1080p) on Ultra with AA turned on and I am getting a solid 70 FPS. Never dips beneath 60 when there are intense particle situations etc.