MicroSoft OneNote

After a few years of ignoring OneNote, I was playing with it this afternoon--I recently acquired a full version of Microsoft Office with OneNote.  It does pretty much everything I need an outliner to do. I don't know if it will import/export to OPML yet.  At the church office, we have Apples and I'm still trying to decide between OmniOutliner and Tree. The difference is about $25.  OmniOutliner is about $40 and Tree is about $15.