I welcome the UI change, but given that, appart from the terrible search, thunderbird has been working very well so far, I'm not going to risk upgrading one of

I welcome the UI change, but given that, appart from the terrible search, thunderbird has been working very well so far, I'm not going to risk upgrading one of my most important business software to something that changes so many things. It will be buggy and slow for a few versions, and likely incompatible with addons. I'll update in a few years.