To be fair: UI (virtual and physical) is hard. Thus far, the AppleTV is my favorite but it's a "lesser of two evils" scenario.
It's purely meant as a mouse-and-keyboard thing, and in that vein it has some failures (the mouse-buttons are face-buttons instead of console-style triggers, and the keyboard lacks a way to use the F function keys)... but in general? I used its predecessor (the N9501 instead of N9502) and found the design lovely.
I could navigate my set-top PC easily with the trackball and mouse buttons, and when I needed to do text-entry I could hold it like a thumb keyboard. I even got pretty far in Cipher Prime's Auditorium with the trackball - it was quite pleasant for low-stress mouse-only games (as long as they only need click, not drag). The problem with my old version was that the trackball was not user-servicable (trackballs get dirty, fast) and it wasn't backlit.
The new one uses a touchpad and has backlighting.
A problem I see is that the tasks of set-top-boxes and displays are relatively constrained, so having a reduced input device seems like a good idea. But how to support free-text searching without a full keyboard (on-screen menus are painful) or having to deal with limited battery life due to a touchscreen?