OneNote has been a great productivity tool, but…
I thoroughly enjoy OneNote for personal productivity. It’s amazingly powerful. For example, if you paste the URL of a YouTube video to a OneNote page, it will automatically insert the video on that page so you can watch it on that page.
However, one feature I’d like to see on OneNote is the ability to assign a page to multiple sections at the same time and, when I update that page, its copy is updated in all those sections. Someone might say I can tag the page, but tagging in OneNote seems more suited to specific items within a page so you don’t lose track of them.