- I don't trust their privacy settings.

- Most of my feed is links to stuff elsewhere on the Internet.

- If I post, I have no idea whether their algorithm will actually show it to my friends.

- I get the feeling their algorithm prioritizes posts with images or video over pure text.

- Hard to post to subsets of friends. I know you can manage lists, but the UI is clunky. (And I don't trust their privacy settings.)