For me at least, they're good popular history - which is to say a robust introduction to some awfully complex topics that they tend to make comprehensible for a wider audience. However, when you bore down into some of the research and occasionally conclusions, you're correct: at times they don't summarize current scholarship and can be uneven.

I'll give a timely example. I quite liked the second of the two Midway episodes (which as of this writing just came out a few hours ago) specifically because of the coverage of the Japanese reaction to the defeat, which was to brutally suppress all evidence of it and isolate and shame many of the survivors. This isn't new and is covered in a decent amount of literature - and our own /u/Lubyak here - but even then still really isn't that well known outside of specialists, and their focus on it for a wider audience is a good thing overall.

The first episode, though? It's a useful illustration of the battle, but they admit Indy never read Shattered Sword and the rest of the team discounted a couple of significant conclusions in it and reiterate scholarship that's not really supported at this point: that the sacrifice of the torpedo squadrons kept the Zeros close to sea level along with the implication that the IJN's carrier decks were crowded with planes. That's largely been repudiated, and our Midway movie megathread talks extensively about how and why the scholarship has changed.

While the Youtube comment section caught that (and the production crew explained why they did what they did in their pinned comment), there is even more recent scholarship like Symonds' The Battle of Midway that incorporates the reevaluation of the battle and refines it a bit - Parshall largely ignores the impact of the low capacity 20 mm cannons of the Zeros being exhausted on the torpedo squadrons, for instance, which probably makes their disastrous runs almost as important as they were under the earlier theory of the battle - along with things like the infamous Flight to Nowhere (ably described by /u/DBHT14 here) by the Hornet air group that helped precipitate that disaster. While I know there's a time constraint on what they can include, both of these are really important lessons about the battle, the scholarship was there, and it's a genuine shame that a series with a decent following couldn't use the opportunity to clear up some of the myths.

As mentioned, bringing relatively more obscure events and analysis like this to a wider audience is something the series does well when it fires on all cylinders, and I've personally learned a ton over the years from it as it's gotten me to go down rabbit holes on areas of both World Wars and the interwar years that I only knew a bit about in passing; they are as good as anyone at making battles comprehensible. But as above, when it gets to areas that I know in depth, they can be uneven; a couple of the interwar videos genuinely made me go 'wait a sec?' given I knew off the top of my head there were a couple of substantial errors that got repeated in them.

Is this worse than other popular historians have done as they've written about events? No, and it's generally far better than most other Youtube series. But much like many other popular histories that I recommend, I'd say this: they're a good starting point, but not the last word, and there's often better scholarship available if you look for it.