Although after many initial trials and tribulations with my 2TB MBL it has eventually settled down and now performs adequately with the exception that I still find Time Machine backups somewhat slow and erratic. Hence I back up to a separate WD USB HD. The one remaining issue is more of an annoyance than a fault and that is how the MBL sleeps or sometimes doesn’t. When you click the Finder window on a Mac to bring MBL out of sleep a little arrow appears above the “Share”. This indicates that the “Share” is connected and has been “mounted”. What one then has to remember to do is click the little arrow when you have finished using MBL which disconnects/unmounts the share. If you don’t do this and simply put the Mac to sleep (default option on an iMac) then the MBL will not return to “sleep” no matter how long it is left. Shutting down an iMac automatically ejects a “Share” so not an issue. This is another reason why you cannot use the option of showing a Network Drive on the Desktop either as the “Share” will stay mounted when using Apple Sleep.
As I say an annoyance rather than a fault but I still wish it didn’t happen.