Maybe the answer I'm searching for is simple:
Paul, the best medium for you is whatever medium will allow you to FINISH something and get it out there.
Can you finish a blog entry without losing interest and moving on? Yes? Great, do that.
Can you finish an eBook and get it out there? Not yet? THen work on Blogs while you try to finish an eBook. If Yes, then get an eBook out too.
Can you finish a Book? IF not yet, stick with Blogs, and eBooks for now.
Hmmmmm....Interesting. Why am I talking to myself on here?
Maybe it will help someone else. Oh yeah, that's right.