I’m been wondering that same thing while developing tvOS app and testing across hardware. What does this new model offer the last 3 didn’t??

Eg Pixel Brite works great on all versions of AppleTV including FEL playback on 1st gen

The only thing I haven’t been able to do with the older models is upscaling content at the same fidelity levels. But the results are very subtle either way and not all that compelling IMO.

[0] https://pixelbrite.site