Match Content is the setting that makes sport look right
Turn on Match Content under Settings, Video and Audio — both Match Dynamic Range and Match Frame Rate. Without it the Apple TV renders everything at a fixed 60 Hz, and broadcast content that was shot at 25, 30 or 50 frames per second gets converted on the fly. The result is a subtle judder on camera pans that most people notice without being able to name, and which is most obvious on football and motorsport.
With Match Frame Rate on, the Apple TV switches its output to match whatever the channel is actually broadcasting. There is a brief black screen at each switch, which is the trade, and it is worth it. This single setting accounts for more of the difference between a good and a mediocre live-TV picture on Apple TV than anything in the app itself.
Which Apple TV, and what the older one cannot do
The Apple TV 4K is the most consistent IPTV device in this list — silent, fast, and with a decoder that rarely refuses anything. The Apple TV HD sold from 2015 to 2021 runs the app perfectly well but outputs 1080p only, so UHD channels will be downscaled. For live television that matters less than it sounds, because most live sources are not 4K anyway.
One genuine advantage of the platform is that tvOS does not evict background apps aggressively, so the app reopens where you left it and the guide is still cached. On cheaper hardware that reload is the slowest part of the experience. If your household changes channels a lot rather than settling on one, the Apple TV feels faster than its specifications suggest.
Audio routing, CEC and the rest of the living room
The Apple TV negotiates audio with whatever it is plugged into, and the default of automatic is right until it is not. If a channel plays with no sound through a soundbar while the same channel is fine on the television's own speakers, set Audio Format to Stereo under Settings, Video and Audio rather than leaving it on Auto — some live feeds carry a surround track that older soundbars advertise support for and then fail to decode.
HDMI-CEC is worth turning on deliberately. With it enabled the Siri remote controls the television's volume and the set switches input when you wake the Apple TV, which removes the second remote from the equation entirely. Manufacturers all name it differently — Anynet+ on Samsung, Simplink on LG, Bravia Sync on Sony — but it is the same standard underneath.
One tvOS habit catches people out with live television specifically: the Apple TV sleeps after a period without remote input, and a long match with no interaction will hit it. Extend the sleep timer under Settings, General if you are watching something you will not touch for two hours.