The Apple TV 4K delivers the best streaming video available to compatible 4K, HDR and Dolby Vision TVs. It offers the most polished streaming experience today, the best remote on the market and excellent Siri voice options. It's just $30, £30 or AU$40 more than the non-4K box
About 5-6 months ago I got an Apple TV through the DirectTV Now offer (prepay 3 months get a free ATV). I have been using it on my main TV and moved my Roku unit to the bedroom. I had been wanting an AppleTV because a few years ago I tried going all in with Apple and iOS. I had an iPhone, iPad, and MacBook Pro and started buying TV shows and movies through iTunes. That didn't last long.
Still have that MBP, and an iMac as well, but I have switched over to Android for mobile. In any event, I had a fair amount of TV shows and some movies I wanted convenient access to on my TV so I figured I would get an AppleTV.
If you are heavily invested in the Apple/iOS ecosystem I think it is a no-brainer. Otherwise, I would recommend against it.
The remote is just awful. Siri works well but it is only really useful for entering passwords and as an alternative to entering text for searching. And while Siri works great for those it not much more convenient than using the Roku phone app. Meanwhile the trackpad on the ATV remote is just terrible for navigating apps. But don't take my word for it, do some Google searches on it.
The other problem I have with it, unless you get everything from Apple (movies, TV, etc), you will find some apps to be limited to view only mode. Because Apple takes a large cut of purchases, a lot of providers have limited the apps to view only mode and you can't make purchases unless you go to their website on your computer.
So for me, I wouldn't recommend the AppleTV. However, in all fairness, I do know someone that is heavily invested in the Apple ecosystem and he loves his AppleTV. Personally, I think that is the koolaid talking, but he much prefers the AppleTV to his old Roku.
Ideally, you should buy it from some place that accepts returns. That way you could spend a couple of weeks with it and decide for yourself.