Hi all,
Some info for you...with sucess (so far)
I ran Doug Adams Track Sift app, bought from app store and cleaned out my dead playlists. It took over night. Ran better than the basic script (which kept crashing out a la automator script) so thanks for that!
Now with a clean local itunes, switching on and off match seemed to do no good and the duped playlists kept returning. After speaking to itunes support they told me my cloud data had been cleaned accordingly and said maybe it was a connection to the data problem....
iTunes on the mac was struggling to connect to the cloud, error 4010, when toggling match on/ off so following some other leads I turned match off, updated genius results from the store menu in itunes.
This didn't work first time so I signed out of itunes, then back in. Re ran genius update, was fine this time. I'm pretty sure I powered down my Mac at some point in this rigmarole!
Eventually, turned on match again and it appeared to sync ok, no duped playlists, iTunes loaded in a sensible time and all my expected playlists are good.
am just about to try turning on my iPhone/ iPad to see what happens...
Hope that all made sens