Last time I spent some time with it, the UI just never clicked for me. My main notetaking device is my iPad with a Pencil stylus and GoodNotes. It does a great job of interpreting my handwriting and then I can export a searchable PDF to Evernote, or I guess, OneNote.
Is the metadata search in OneNote decent? For example, can I search for notes I created in Houston?
Don't think so. You can search note titles, bodies, section names, section group names, handwriting, OCRed text in attached images (OneNote can embed pdfs as attachments or insert a printout of the file as images, it doesn't have an inline pdf reader yet). It can't search inside attachments or inside cloud attachments.
The app has its own tagging system that lets you attach tags to eg. paragraphs and the desktop clients have tag search and custom tag creation. The desktop and mobile apps both also have search that treats "#word" and "word" as different things, so you can jury-rig a hashtagging system should you want to.
Now it seems they've completely fixed them.
Also, initial sync on a new machine is ridiculously slow. As in I need to leave it for hours before it totally syncs everything.
It's not quite as feature complete if you're not using Office, but it's still pretty handy.
It's true the app's positioned as an online service rather than a file reader for offline files the way it started, but calling a native app that operates on local data a "thin client" is just disingenuous.