The one glaring problem I see with evernote is that I cannot edit a note from two different devices without first syncing it on both devices, which takes at least 15 seconds to do.
It's SUPER annoying to have to stop and wait when I need to drop a file from my laptop into an evernote, while working on that note in my desktop.
In my mind the solution is simple; allow for simultaneous edits, the way google docs does. This way, I can add text, files, or whatever else into the evernote from any/all devices without having to stop and wait, and then I don't have to spend so much MORE time dealing with 'conflicting notes'.