We've used Notion as well pretty extensively and actually have an integration in Dart with them. From my current experiences Notion AI is mostly helpful for brainstorming, document editing, and search (for example to help with finding relevant info across your company docs). Their PM tool is more of an open-sandbox approach that doesn't always have the most robust features in any particular direction but is very flexible and easy to try out different templates for.

We have a bit of a stronger emphasis on personal and team task management with less of a sandbox-feel and more of an opinionated-PM feel, and our AI features are in line with that with stuff like task property filling and roadmap suggestions. We also have similar capabilities in AI doc editing (although Notion and other tools are definitely more fleshed out there if your use case is primarily writing).

That being said it's a very quickly evolving landscape and I wouldn't be surprised if things change in the near future. Would love to hear anyone else's perspective as well who've either tried both or used our integration.