I use Paper more and more these days with my team though we are into Google for Work. Google Docs is a tough cookie and an office replica.
Those who are in to markdown, they would hardly go back to anything else for formatting. The only catch with markdown is about creating tables Dropbox paper has nailed it pretty well.
The product is more pleasing for eyes with better typography, cleaner design and user experience. There's no friction to write. The people who collaborates are more productive easily review and feedback. Also it's more developer friendly with quick emojis with ":" shortcut.
Finally nothing beats the simplicity of Dropbox Sharing.
The product has lot more opportunities to grow. Expecting more integrations in the coming days.