Played around some more with my Ultra today, and the unit has some major issues that I hope are addressed in a future firmware update, as I had tech support open a ticket.
1. The Roku Ultra does not like 4K HDR displays unless they can support 60Hz natively. Otherwise, it will auto detect them...
Roku devices, by design, are "always on" devices with no real power down sleep modes, which both Firestick and Apple TV devices have, so they can be prone to overheating if used extensively in a warm environment.
When my Premier warned me of overheating, I unplugged the unit for several hours...
I had that happen recently with my Roku Premiere, but it was an unusually warm day, we had not turned on the AC, and had been streaming a lot of 4K content that day. We unplugged it for a few hours and haven't had the issue since.
I ordered the Ultra today, and debating on if this will replace...