BobL...
+1
spot on!

I have not seen a Sony 4K and JVC 4K close enough to make a decision personally. But what Bob said is 100%, resolution is only part of the equation - a small part of the overall equation to picture quality. If everything else about the picture is crap, it doesn't matter how high of resolution it is = it's crap.
Not saying either one of those projectors are crap, in fact both are pretty good. But the people arguing the Sony looks better just because it is 4K vs. 1080p of the JVC... I have to wonder seriously about the other stuff you peddle to your customers.