I bought Apple TV years ago and have model A1427, which I believe is referred to as second generation. What new features would I pick up if I buy a new Apple TV device?
The current version is a 4K device. This means if you have a 4K TV you can upgrade the output from 1080p to 4K. You also would get some on-device storage with the new one. Though with the new one you lose the optical audio port.