I just wanted to add my two cents.. I chose Onenote over Evernote based only on subfolders/hierarchy.. Albeit onenote doesnt have much beyond three levels deep (and even the 3rd level of hierarchy is barely noticeable).. My friend is considering Evernote for the Mac but immediately was upset when it revealed no support for subfolders. It has everything but it! She wants to create 100+ notebooks but knows how cluttered it will look.. when she hoped to break them into about 10 categories.. For cleanliness subfolders are needed! She tried the tags and got more confused.. Why should she have to set the tags manually for each note she adds? When she should just be allowed to "select" on a certain notebook and hit add... then it will know file it in that same sub-notebook... without "tagging" it (another tedius chore). +1 vote for subfolders Thanks!