The limitation is a 2K (i.e., 1080p) panel only has 1/4 the number pixels of a 4K panel (2 Mpixels vs. 8 Mpixels) thus the combined image from the two 1080p fields only has 1/2 the number of addressable pixels as does a native 4K panel. The projected eShift image may even have the visual appearance in terms of visibility of pixels, smoothness of the image, etc. of a native 4K image, but it will not equal a native 4K image in terms of absolute resolution as it cannot display some very fine details when there is some pixel scale details present in the 4K source image. Don't get me wrong, I think the lower end JVC eShift projectors with a 4K signal input have the potential to provide a lower cost alternative to a native 4K projector while providing perhaps 75% (???) of the benefits I am disappointed however that it appears that JVC's new projectors won't have HDMI 2.0 inputs and it they also lack support for HDCP 2.2 then they may not work with some future 4K sources, such as Blu-ray 4K.