If you copy text from an outside source and paste it in the HTML pane, it retains the formatting from the source. This creates extra time-consuming work because you have delete unwanted spaces and change font styles and sizes. I'm not that particular about fonts but it quickly makes your notes look like a disorganized mess if they're in a random assortment of font styles and sizes.
I have a suggestion which would help users avoid a lot of tedious re-formatting. In OneNote, when you paste an item, you're given the following choices:
1) Keep source formatting
2) Merge formatting (ie change formatting to match the existing formatting where you're pasting the text)
3) Keep text only (removes any images in the copied material).
The first two would be big time-savers, I believe. The third one would be nice, I guess, but not as important.
Wayne