I wouldn't say mind-numbingly slow, but it does struggle sometimes. The Android app is a bit poor as well in my opinion - gets the job done, but I've seen better ones by competitors.

Despite those issues, I have fully switched over to Notion. Instead of trying to force some very specific workflow onto you, it just offers a great toolkit that you can use to manage your own work whichever way you like it.

I would prefer a native app over a web app, but I guess that's just the world that we live in today.