Skunkie Designs Electronics did an extensive series of tear downs and reviews on both the Willsenton R8 and the Muzishare X7 over a period of months. It seems Willsenton took some of her feedback to heart and changed a few things in their circuitry to make it better as she suggested.
Here is a link to one of her videos. But note that there were other ones later where she applauded Willsenton for upgrading their design for safety.
Even so, while she liked both of these at the end of the day (after mods) she stated that well, nothing in life is free, and the quality of the transformers on tube amps means about as much as the quality of the tubes. Neither one of these is a "giant killer", but they are nice at their price points. Many people have bought them and enjoy them.
https://youtu.be/fjGefU2qB-0