ATV4K is best for OTT streaming while I use nvidia shield tv pro for local content streaming off of a NAS and HDD. As mentioned earlier, ATV4K has an edge over other devices especially streaming ATV+, Netflix, PrimeVideo like contents in India. Nvidia shield is very good if you watch a lot of BDRips and also share that with other friend via a Plex server.
I've recently tried using Plex client on ATV4K (ATV4K plex client streaming from Plex server running on nvidia shield tv pro while content is on a NAS) and it was good experience, need to try more before I can comment, I have used Infuse pro on ATV4K in the past for local streaming, it was great but not that feature rich as Plex client. I guess when I use the plex client on ATV4K as I mentioned above, it does some transcoding and may be loosing some quality / performance there, need to get into more details on that part but if that one device can do all, it'll be great!
I have no experience with Ziddo.