I replaced my 3rd generation Apple TV with a new 64 GB 4K device. We use a universal remote to control all of our devices. Cable is assigned to HDMI 1 and Apple TV to HDMI 4. When you choose Apple TV on the universal remote, all of the related devices (e.g. AVR) are adjusted to accommodate Apple TV. After the initial Apple TV set-up, I noticed that when you hit the screen button on the Apple TV remote, it automatically makes all of the required changes, including switching from HDMI 1 to HDMI 4. At first, I was kind of annoyed, but it is actually a pretty cool feature.