I can't really imagine what you believe is so bad about the Apple TV UX. It's a basic grid of available apps and videos, with an easy swipe to access video settings (subtitles, language, etc). Not complicated at all.
Most streaming boxes have the same basic interface... my usual issue is when one is laggy (e.g. TV built-in, Roku, Chromecast, etc). The Apple TV is buttery smooth, fast to scrub through videos, and never feels limited by its CPU.