For me that meant 30 GB of podcasts gone, most of which I can't download again (publisher went broke, original download required payments etc.) Sigh. I used to be a big fan of iTunes as well.
Podcasts used to be simple: follow an RSS feed, download the audio files, listen to them, delete them when you're done. Now they're "cloud," so your computer is just a cache, and God only knows when you have those files, or when some program lets you use them.
I would argue the peak in bug severity was 11.0, which randomly deleted podcasts: https://discussions.apple.com/thread/5324634?tstart=0
For me that meant 30 GB of podcasts gone, most of which I can't download again (publisher went broke, original download required payments etc.) Sigh. I used to be a big fan of iTunes as well.