Apple TV UI I would say is pretty close to perfect. You can do everything intuitively, with one hand, in the dark, half asleep. I don’t think I’ve ever had an issue figuring anything out. It’s pretty simple, but yet I can watch anything I want anytime I want so I’d say pretty powerful. Mine is an old version though so maybe I’m missing some features and functions. I only use Netflix and iTunes on it. Youtube the odd time. All the other apps on it are useless and wish I could delete.
R