nVidia Shield or Apple TV

I have been using Simple Control (Roomie) for a number of years now, with a nVidia Shield (2017) box.

I am in process of upgrading my system and wanted some opinions on whether to stick with the Shield or go to Apple TV. At the moment the Shield is good (mainly used for Plex, Netflix, Amazon Prime) but the connection via IP control is fiddly at times. For example often the USB Debug message will come up for no reason and I have to run to the loft to turn it off etc

Given Roomie has typically favoured Apple (particularly from the Phone OS point of view) I'm wondering whether my experience all round would be better with an Apple TV?

often the USB Debug message will come up

That's a V5 bug. So your first priority should be to upgrade to V6 ASAP.

You're not going to find a perfect answer to this question. But yes, Apple TV is the best choice for control without a doubt. When you get into the details regarding Atmos, Dolby Vision, etc., Apple TV becomes less of a good choice. OTOH Shield is imperfect on DV as well, and only the new Shield Pro supports any sort of DV.