dear ozdazza,
I installed 11.3 on Friday July 11 in the morning, realised in the evening when I got home that the system beachballed and beachballed to the point that the ventilator couldn't cope any more and all I could do was force quit and give my MacPro 13" and its 4 GB RAM time to cool off.
Saturday morning I tried again, realised that the automatic update I had chosen provided in List-View Settings would go on beachballing and thus I'd never have a chance to switch it to manual and thus be able to look at what was going on. So I called the help desk. Verena made me do something which I forgot to remember or was it the deleting of files in Systems at 3 different locations which did it. Anyway I was able to open iTunes without it starting beachballing immediately and I switched the settings to manual. Then I showed her the problem while she was switched on and she decided to update or re-install or whatever OSX. By then 5 hours had passed and her working day was over and the updating lasted 2 hours anyway during which nothing could be done. Sunday was her day off and she promised to call me again on Monday after her shift started at noon. Never heard from her again. By then I had realised that more hours with her on the phone were useless because she had convinced herself that with my collection of podcasts I should have a 16 GB RAM model (price 2.600 € instead of 1000 for the current model I have which is already about more than double the price of an equivalent PC). After having slept on it that advice told me all I needed to know (and by then I had gone to the communities threads where somebody's remark that updating all in My Podcasts View didn't lead to excessive beach balling)
Whatever I have read here (with the exception of your experience in Japan) tells me that Apple will never admit that it did me wrong.
Oh and Verena told me another thing that my habit of deleting so much is likely to damage my hard drive while at the same time she thought a 500 GB hardrive would provide me with enough room so I wouldn't have to delete - the absurd thing is that now Apple itself provides in MyPodcastsView a choice to automatically delete stuff that has been listened to.
As soon as the lovely summer weather is over I'll go to the local computer shop and have him help me set up something suitable for me. My trust in Apple is gone. I am no longer the kind of customer they are interested in. I fell in love with them through Podcasts on iTunes on my Microsoft laptop and I fell out of it through Podcasts on iTunes on my Mac.
and BTW I'd never have expected them to sink so low to put the blame on the customer.
and another btw that 5 hour long session with Verena did my humble little inadequate (by her standards) machine a whole lot of good.
Good luck to you with yours and congratulations that you have helpdesk personnel that is willing to acknowledge that Apple may have made a mistake.