The Atom has been around for awhile and there are multiple positive video reviews online for it. There are multiple variants of the Atom though and they don't all have a 3-axis stabilized gimbal so that's one thing to watch out for. Many of the reviews I watched said it's a reasonable option to the Mini, but without as good of picture quality or as refined of a flying experience. But typically they end by saying something like, "If you're looking for a decent sub-250g drone that won't break the bank, the Potensic Atom should be on your short list."
I do not have first-hand experience with it though. I purchased a Walkera T210 Mini mostly for the price and to get the VR headset and motion controller, which other non-DJI competitors don't offer. It's fun to fly and definitely wants to be a DJI Mini when it grows up, but it's still not as refined as DJI products. Walkera has been pretty good with firmware updates and is certainly modeling the UI after DJI's, but oddly it and parts for it might be even more difficult to find in the US than a DJI.
-Rod