All the NFZ instances, loss of connection (could be app issues?), reduced signal strength, resolved when FW rolled back, various erratic flight control issues.
The mere fact that you're re-loading firmware onto a chip can increase the risk of data corruption. I'm not saying I never update anything, I just pick my battles if you will.
The gain vs risk scenario is something I run through my head. What will I gain by updating and is it worth increasing the risk I may experience the issues others are reporting.
All it takes is one of those 1's or 0's being out of order in the code and I've got an expensive brick falling outta the sky.