There seem to be various problems with TVML on the 4K Apple TV, that mean your app using TVML can't look as good as a native app:
1. Text Rendering: Almost all of the text in TVML is rendered at 1x, and so looks fuzzy on close inspection. Interestingly, some parts render correctly at 2x, eg. descriptions on product pages, and scrolling title labels _once they begin to scroll_.
2. Image Rendering: Whether you use 2x images as the src attribute, or you use srcset with 1x and 2x images as recommended by the documentation, images are still rendered at a lower quality resembling 1x.
These problems mean that TVML effectively renders your entire interface at 1x.
This seems to be true for tvOS 11, and the tvOS 11.1 beta 1.
Hard to believe that TVML is a supported way of developing tvOS apps, and yet effectively doesn't support the Apple TV 4K!
Filed two radars about this:
rdar://34625629
rdar://34711443
