Yes, very much so. Some of that would depend on the monitor, but it still would not be pretty.
I strongly reccommend waiting till there's a decent 4k monitor with G-sync out there. It really does incredible things on a monitor that's a little too strong for a card to make use of.
Also, check out things like the Asus Swift - I would much, much rather have a 1440p, native 144hz, g-sync, 8-bit panel than a regular 2160p, but only 60hz with no features.