I remember that video now, I have seen it. He does seem very knowledgeable, and he has another video titled "Disassembly and Care of S&W revolvers" that I found very well done.
He still doesn't convince me that the new production guns are better than those made earlier. He even mentions, at 7:55 into the linked video above, "a lot of these problems....someone who owned them created." As an armorer, he sees the problem children, so he knows what can go wrong with one, either from poor design or mishandling or abuse. But that doesn't necessarily mean that what he sees wrong with those guns applies to all others as well. How many M19's, for instance, has he worked on, compared to how many M19's that are out there and have worked flawlessly since Day One?
I see this on car forums all the time. There may be several people who have a particular car write in and say "such-and-such keeps breaking/burning up/falling off my car". It would seem to imply that these problems are endemic to that model, while they are issues that may come from causes not related to the quality of the car, but from abnormal use, abuse, lack of maintenance, etc. Of the 3 or 4, or 10 or 20 , people who write in to agree or complain about such a problem, how many are out there who've never experienced it. Are they going to write in and say, such-and-such has never broke, burned up, or fell off my car? Probably not.
Time will surely tell. 50 or 60 years from now, let's see how these new-built MIM/CAD-CAM, two-piece barrel, CNC guns stack up against what S&W has built the old-fashioned way for 150+ years. Maybe they will be better, maybe they won't. Even if they do, they'll never develop the character of the older hand-fitted ones, IMO.
-- for why current S&W revolvers are better than usually given credit for, and in certain ways equal or superior to their predecessors.
