Not a big fan of his overarching narrative, especially in matters of history.
He lavishes glowing praise on anything anarchist in a way that is entirely blinkered to the realities and is without critical analysis. For example, he will extol the virtues of the economy of the Spanish Republic but he refuses to actually engage in the (scanty) historical scholarship and acknowledge that there were critical flaws within the Spanish Republic and clear problems especially especially to do with labour discipline, or he will deny the Eichenfeld massacre.
He's extremely dogmatic.
I have had very productive discussions with anarchists about these sorts of matters. If you can acknowledge that an anarchist revolution is going to have excesses and that, historically, excesses have occurred and that they need to be learned from in order to mitigate the risk of them happening in the future then we're going to get along just fine.
If you look me dead in the eye and deny the Eichenfeld massacre or claim that valid criticisms of Makhno's personal conduct as de facto leader of the Makhnovshchina that came directly from a member of the Military Revolutionary Council are merely Bolshevik propaganda, without actually having done any research into these things, then we are not going to get along.
In my experience, Anark falls into the latter category. He is not a person I would be comfortable with even back when I was an anarchist.