I've been using Tbird since forever, the past 6-7 years on Linux (Debian/Ubuntu downstreams). A couple years ago, I think during the 68-71 release cycle, there were are lot of panicky blogs about "don't upgrade; the new Tbird will irrevocably screw up your Contacts/Calendar/Other Plug-ins", I may even have tried it and experienced issues myself (I don't recall) ... and as a result, I've held my copy at the 60.something release since then.

Now the 91 update has been out and stable for awhile, and a major overhaul upgrade to 102 is in the offing ... and I'm looking for feedback ... is it safe to upgrade? Might I still hit breaking issues? Or was it always safe?