Selfhosted

ATV is the only box I recommend. I'm anti-Google, don't trust Amazon (and now their service is going to do ads on a paid Prime membership), and Roku has major privacy issues at least in the past. Curious why you're seeking an alternative to Apple.

I have tried Roku, Fire TV, Chromecast (not the new models with an interface), and AppleTV. So far Apple TV is the cleanest without ads or sponsored content on the home screen.

If you find something better please let me know.

Keep your Apple TV and use it as a streaming client for whatever you stand up on the backend. Personally I have a Synology NAS that I love and I use the net to get all my content. Use the net. 😉

If you have Apple users at home, the integrated experience and the video quality is going to be very hard to match from other platforms. My parents use Chromecast and it takes so many more steps to send content on to their media system. The video quality when casting also suffers a little, though that may be because they’re using cheap ISP router AP combo box, and I’m using Ubiquiti APs instead. Having said that, I do think the A15 processor in the most recent model is an overkill in the graphics performance department, so I wouldn’t completely rule out device capability compared as the cause of video quality difference.

Based on my readings, I think most recent high end nVIDIA Shield Tv Pro is the only closest in terms of raw performance and even then it may be a bit behind. Tegra X1+ found in the Shield Pro is on Maxwell architecture, which is older than GeForce 1080 series’ Pascal architecture, if I’m not mistaken. This would date it to around 2015-ish; whereas the previously mentioned A15 processor in most recent version of AppleTV 4K was introduced in 2021 with iPhone 13 series.

I have had various sticks and Roku highest end models and then got the latest ATV with hard wire port that adds Dolby vision and high frame rate HDR. I have a 2022 high-end TV.

The video quality is noticeably better. Not sure of older ATV, but this is clearly better than the top end Roku. Also, I'm not sure if it is the same on older tvs

The other thing is that you want to hard wire if at all possible. Even the best wifi can't touch the reliability of a wire

Not sure if it's a factor for you but roku tries to phone home a lot more than anything else on my network (or perhaps my firewall just catches it more than other devices and apps). Otherwise roku is pretty good.

Nvidia shield tv is better though. It's the best set top box. Made even better by replacing the default launcher/ home screen (android TV default launcher now has 2/3 or more of the screen taken up by ads or "recommended content" which is just ads).

Nvidia Shield Pro with the default launcher disabled & replaced, Plex server. I'm pulling the unused apple TV out of the media setup this week.

I host a Plex server for streaming and my apple TV 4k 2021 would refuse to play high bit rate media. Kept displaying an error message telling me I've exceeded the limit. Started searching online and everyone consistently called Nvidia shield pro the best one can buy. Bought it, love it, now have 3. But all I use it Plex. I've made my server basically all streaming services combined to one.