Another voice for sub-notebooks. Tags are extremely useful, but on their own they are restrictive and unintuitive. Folders and sub-folder mimic the way the human brain works, there is no learning curve involved. Products that force the user to work in an unfamiliar fashion frequently fail. Apple's success is largely due to making computers, and phones, work in an intuitive, human way. Apple products are rarely the 'best' product on the market, but as far as usability is concerned they are unbeatable. They work for you, not against you. Evernote is an excellent product, but there isn't a day