Of course HDR10+ is available, my OP stated it plays in HDR10+ when starting movie from continue watching, tags only HDR10 though when playing from my library.

4K SDR resolution and set match content and frame rate to ON, 4:4:4 if available and make sure you have a quality certified HDMI cable, ATV 4K boxes can be finicky with cables.

First off, apps open faster and are much smoother running, super fast navigation, picture quality is great, good UI and if in the Apple ecosystem the experience can’t be beat.

IMO it’s always worth buying a Apple TV 4K, great device, super fast, seamless UI, no ads and great picture quality in apps, people suggesting using built in TV apps clearly have never used an ATV 4K box. If op is tied into the Apple ecosystem it’s a no brainer.