You could probably just save yourself some time and read the Youtube comments. You’ll run the whole gamut of Catholics and non-Catholics who are either enthusiastically endorsing or critically reaming Mike Gendron, with every other type of opinion in between.
(Though, to be fair, the mere fact Gendron is an ex-Catholic doesn’t inherently make his opinion about Catholicism more or less trustworthy, any more than the opinion of a convert from a Protestant denomination to Catholicism makes their opinion about Protestantism more or less reliable.)
True. But the fact that he is an ex-Catholic does make his opinion more trustworthy than that of a non-Catholic (see above for some of those).