I've been using Notesnook for nearly a year and I'm really happy with it as well. Very feature-rich and easy to use despite a focus on security. I had a scare recently with an important note seemingly disappearing, and I was saved thanks to a really nicely implemented note history functionality that I didn't even know existed.

I will say that some of the design decisions can be a bit confusing, so it's worth testing it out before buying. Even a year in I find myself a bit thrown off by how exactly the relationships between notebooks, topics, tags, etc are expected to work.