marshal11 :
Well it is a 4GB card. A 4GB 770 in Canada costs 450$. A 4GB 760 is 300$. 150$ isn't worth it, especially if it's a well overclocking gtx 760, because it will surpass a GTX 770 with a factory OC too. And I can tell you that my GTX 680 lightning (same as a GTX 770 lightning) which has 2GB of RAM can't run BF4 maxed out because it runs out of V-RAM on 4xMSAA. It'll run a steady 60FPS at 4xMSAA at 1346/7Gbps, but once it runs out of V-RAM, I get constant drops to 5FPS because of the GPU freeing up RAM. 2xMSAA stays at a max of 1903MB so far. In other words, 2GB is outdated for games that are capable of running games maxed out. You need at least 3GB of V-RAM on a high end card. Therefore, I'd take a 4GB 300$ 760 which overclocks like a beast over a 2GB 770 for 20$ more any day of the week.
So many people get hung up on RAM. AMD has more RAM that NVidia in general, it doesn't make the cards any faster (unless you are Bitcoin mining).
2GB 770 is faster than 4 GB 760. 3GB 780 is faster than a 4GB 770. See a pattern here?
More importantly, a 2GB 770 is equal to a 4GB 770 in 99% of scenarios (in some cases, the 2GB is actually slightly faster).
And then there is the "future proof" argument. I personally do not think "future proof" and "graphics card" should be used in the same sentence. Well let me pay an extra 50$ for a 770 with 2GB extra RAM, so I can sli later... No thanks, I'll save my 50$, and apply it towards my next generation single-GPU solution. The GTX 770 is plenty fast right now at 1080p. In a few years when it starts being slow at medium settings for modern games, I will get a new 970 or equivalent.
For those who must have the latest and greatest, or use higher res or multiple monitors, buying a lower end card like the 760 with extra RAM isn't the solution. 780ti, or soon the 790, would be the route to take... And sure, the 4GB 770 might give a few extra FPS on multiple monitors on certain games in a perfect world, but the frame rate is still unplayable on 3 monitors, so it's really not worth talking about.