I’m going to wait for my 4K Roku. Coming Soon, I think.
I just hope it will have a dedicated digital audio output.
I have both Rokus and Apple TVs (neither is the latest just out). Roku does poorly in comparison to Apple TV. I rarely watch Roku any more, except when I get an urge to play Angry Birds on it. Borrow an Apple TV and try it, or use a friend's Apple TV and you'll see what you're missing by getting the (inferior) Roku.