For what it's worth, for me personally the appeal of this function is not about how long it takes to empty the import folder, it's about the reassurance that Evernote has actually seen and imported a given file before it's deleted. I worry that if the sync got interrupted or that somehow a file has been missed, and I then go and empty my import folder I might not realize until weeks or months later that I've lost that file. That's probably just me being paranoid about the reliability of the import function, but it wouldn't be the first time I've expected to find something in Evernote, only to realize it's missing. So, Evernote deleting a file after it's been synced just gives me more peace of mind than if I delete the files myself, assuming they've been synced (and not wanting to cross-reference each one to make sure it's been imported).