Planbook?

I have been feeling a bit overwhelmed with paperwork lately.  I feel like I am a doing  a lot of "doubling up."

1. Lesson plans sketched out in my paper calendar (I can't get rid of it)
2. Typed lesson plans in Google Drive.
3. Weekly overview typed in Google Drive.
4. Lesson plans linked to my Google Calendar. 

Last week I was introduced to Planbook.com and it looks like something I might like.  I was just wondering if anyone out there uses it and what they think of it?

p.s. Art pictures/projects coming tomorrow!