It's very promising tech, IQ is fantastic in Hell Let Loose. I feel it just needs more scaling options and as you said hopefully more performance optimisations. I think I'm running from a fairly high native res to begin with, 3840x1600, which scales to 5120x2133 x1.78DL or 5700x2400 x2.25DL which are still rather taxing. At lower resolutions you may not see as much of a performance hit as what I'm seeing.
Oh can't wait to try that out in HLL since the standard AA implementation is pretty awful.