Dynalist is better in almost all respects. It's also by the same creators of Obsidian. In fact one possible con is that development pretty much halted now that they're focused on Obsidian, but it's still perfectly functional and featureful.

I'll put in a word for Checkvist (https://checkvist.com/). I find it the best of the online outliners, which manages to improve year on year while maintaining its fundamental virtues (notably - it's the most keyboard-centric web app I've used). I noted (with a slight shock!) recently that I've been using it since 2015.