I have access to 4k material via Prime, Netflix and more recently Sky Q. I think I know the answer here, but I'm just wondering if it'd be worth me picking a UHD version of a movie to watch on Sky Q, rather than the standard HD. Does down-converted UHD resolution look better on a 1080p panel? Does the improved colour gamut in UHD carry over? 
EDIT: Going through a Marantz SR5012.

EDIT: Going through a Marantz SR5012.