Yesterday I tried this out with FL Vanilla shader and it looked pretty good to me.
It is sampling as ex. a 4K monitor to a 1080p monitor picture. I read that it's an easy way off "reviving" old games in general.
My GC is 2x GTX 660 Ti and did have problems with 2x and 4x sampling
AMD calls this Virtual Super Resolution.
read more @Dynamic Super Resolution Improves Your Games With 4K-Quality Graphics On HD Monitors | GeForce