My two biggest issues, skimming the website:

- this does not seem to be open source or free-as-in-speech. That worries me - especially when it comes to longevity. It's the reason I wouldn't use this product if it was by Google.

- i don't see an easy way to export my data in case I would like to migrate to a different service.

That being said I am definitely going to try it out and see what it does for me! There is definitely a gap in knowlege-mapping software in my life