Retroid and the newer Anbernic devices running Android don’t appeal to me as much personally. I really like the charm of a dedicated Linux OS. Just something about connecting my Google account that really kills it for me.
Aside from that, retroid makes pretty solid devices too from what I understand.
The interface on the Miyoo Mini (with OnionOS) is a lot smoother and more streamlined than anything with Android. I definitely like how easily you can switch between all your recently played games so quickly, regardless of system.
Android devices tend to be a bit more flexible/powerful with more emulator options, but the interface isn’t as complete and more tweaking is needed. It’s not perfect, but I’m enjoying Diajisho.
It seems pretty common to use a different Google account on your device than your main one. I only use it to access the Play store, then I disable all Google services until I need it again.
But there’s really no right or wrong approach here, as long as you’re playing games and enjoying it.