I run AmberELEC on my 351V and have a Miyoo Mini+,I just really like how OnionOS boots you straight to your game and I use the game switcher a lot on the MM+. AmberELEC is good for tinkering but I guess I just like the simplicity of Onion OS for quick pick up and play sessions.
Same, I’ve been dabbling in these handhelds for about a year or so now and I always tend to go right back to the Vita, it’s such a solid device.