Up to batch four had problems crxess I know because my friend had one that burnt out and it wasn't one or two either by vaping standards quite a large number of them had the issue into the hundreds. I don't like exaggerating rumours but I also don't like underplaying something either and if given the choice I'd rather overplay and no one gets hurt then underplay and risk it each to their own.
Funny you should make this statement when everything pretty much flat lined after the updates. There have been a few reported incidents of Charge port failure on units while attempting Passthru while charging - something I recommend avoiding - beyond that there have been no Run issues of public note(postings) of any sort since Batch 0002xx
Not sure why you say well over 100, maybe Total units with some defect?
Even if you include all failures and reach 100-150................ out of a production nearing 1/4 million, that is extremely LOW.
It is likely 10 times that number of iStick 20's are already in the Trash or junk drawer, however a million plus have likely been shipped.