I haven't tried all of those so I can't say from first-hand experience, but I get the impression that Office Lens offers a higher degree of integration with the Microsoft family of Windows desktop/laptop applications -- which is why I thought it would be of interest to the Windows Ping List folks.
Maybe you can tell me: do those other iOS scanner apps integrate seamlessly with OneNote, PowerPoint, OneDrive, etc.? (I'm not saying they don't, just saying I don't know offhand.)
You basically take a picture of a document, and it saves it as a pdf file that you can upload to your cloud (dropbox, box, skydive, iCloud). Some are slightly better than others, but they are all pretty much the same. You click the share button, and then can send it wherever you want. I’ll see if Lens has any features that make it better.