Maybe it does not support 4K right now but it seems to do everything else right! Perfect UI, reliable, great design.
If it's 4K that you want and your eyes can see the difference that HDR brings, then wait until September (only 6 weeks away) for the possible new Apple TV.
I'm sure that when it launches, people will then moan that their WiFi is slow, it buffer or they won't pay the price of 4K films. 🙂
To me, the Apple TV is perfect!