Although I have a HDTV near to my monitors, I'm using a trick that speeds the debugging process.
As it has been said in the forums, you can record the Apple TV Screen using Quicktime Player on El Capitan. It is true... and the best is that you can also preview the window in your screen. So the steps are the following:
1.- Plug the Apple TV to the TV and the computer
2.- Open Quicktime Player, and dismiss the file selection window (click on Done)
3.- Click on File -> New Video Recording in Quicktime Player
4.- Click on the down arrow sign right to the record button, and choose 'Apple TV' in the Camera
5.- The Apple TV screen will appear in the window at full size.
6.- Scale the window as desired (yes, a small window looks nice). Remember, you can float the window over any other using the Quicktime menus.
7.- Run your app in XCode 😉
The pros:
1.- You are 'simulating' a full featured simulator in the same coding screen, with Metal/GL/Scenekit/etc...
2.- You have your remote working at 100%, even with Siri.
3.- If you are testing with gamepads paired with the Apple TV, the same of above.
If your TV is not near to the dev computer, I'd suggest you a simple usb extension.
Just my two cents (and my setup 😉)