OK, so I bit my tongue and bit the bullet today. Updated my 2nd gen MyCloud to OS5. Sorry to post here on the old OS3 forum, but the folks here appear to be a little more knowledgeable and responsive than on the OS5 forum. So far just one issue. When I access the drive remotely (or through mycloud.com), I can see the “Shared Pictures” folder in the shared “Public” folder, but not “Shared Files” or “Shared Videos” (or anything else in the shared “Public” folder).
When I updated the MyCloud and set up OS5 I was asked to share the pictures (which I did) but nothing else.