We've been managing projects using Apollo at MADSOFT for over 6 years now. I see those kinds of posts often and, for some reason, I never, ever see Apollo mentioned and I'm not sure why.

They're continuously improving it, adding new requested features, and it's very streamlined and easy to use. We use it for everything: tasks and milestones, file version control, project-related discussions, contact management, project events and timelines, etc. It's pretty cheap too.