That's the first time I have heard about them but it looks very interesting and pretty. Synology has become way too expensive for me as I only need a 4-bay NAS and Ugreen is cheaper than the Synology. My only concern would be the software itself, and if they can avoid all the security holes that plagued some brands like Qnap.

Last but not least, they seem to have Docker support which was restricted to more powerful Synology models, and it's a nice bonus for self-hosting nowadays.