Too expensive by half, and I don't think it is client side encrypted which is a deal breaker for anything sensitive. I really enjoy the simplicity though, great for checklists, writing papers, and all those little rare but important non-calendar based lists, ie. books to read, music to buy, etc.
My ideal note-app would be like workflowy, but allow de-hierarch-ising the list mentality. I mean, workflowy is basically a database back end and I can link tags between lists. But why not just have all the tags separate in the first place? You could have the constructed hierarchy tree to the left (ie bullet list), and the links tree to the right so you can see how the entries both compose and decompose.