I am sure this has been asked before but wanted to pass along my opinion also. I really struggle with the fact that both tags and notebook stacks have a depth limit of only 1. Maybe I am missing a critical part of how to best utilize the evernote label system but this seems like a silly limitation to me. I'll provide an example of how I have utilized other note systems in the past which I have personally found very useful. I like to categorize my notes into various subjects of which some categories I may refine those subjects into further sub-categories down to the grand-child or beyond if necessary. I fully understand that labels can replace these names but as far as I can tell I see no way to relate or group labels to other labels (other than 1 level deep limit) the way a normal parent - child structure can descend into. For example I have a folder called Tech of which there are sub-folders called Windows, Linux, Mac, etc... in the past I would create sub-folders in Linux called programs and even another sub-folder for each program I wanted to keep notes on. Now some of these programs may have further sub-categories that are appropriate to that specific program. Of course I can label each level but if a person has tons of notes in which each may have custom categories other than maintaining an amazing memory of which labels were used where I don't see any way to dig down to a subject level and see what groups were built originally and view just those notes. The evernote search system is great and labels are a nice plus but in some cases a simple global search across all notebooks or working on guessing what groups of labels where used in old notes ends up not being the quickest way to find a specific note.