Currently midway through the 1st book... Had it been generic fantasyland, it would be rather good. As medieval ANYWHERE it's laughably bad. I mean he got some things right, like horses (except
that one) not being motorbikes, his knights actually wearing gambesons, and so on. But he got much more things horribly, that is absolutely, wrong.
Like his description of medieval swords and swordfights. Early XIII-century bastard swords made of wrought iron... (Ok, longswords started to appear around then, but they weren't common.) Shields not used in swordfights AT ALL. (I mean, knights just carry them around. Halfway through the book and after several battles no one parryed anything with a shield.) And so on ad nauseam.
Or the simple fact that contrary to author's belief 13th century Polish language won't be readily understood to someone who knows just modern Polish.
(Like Russian, Polish dropped aorist and perfect tenses sometimes AFTER the 13th century, not to mention subtle shifts in meanings and pronounciation, dialects, loanwords, etc.)
Granted, Old Polish is much more understandable to someone knowing just modern Polish than Old English to an average modern English-speaker, and true, you can kinda-sorta understand any Slavic language knowing just one (I can.), but you won't be
fluent in it, like Conrad is, from the get-go. And Conrad's constant references to "grams", "liters", and in one case "cents"(!) in his dialogue, which are apparently understood by the locals, don't help a single bit.
Speaking of which medieval girls don't use words like "fantastic". They really don't.
And speaking of "cents," - Money in the series might be as well called "[Metal] Pieces™" They are treated exactly as if it was a D&D campaign ran by a DM who was very lazy.
And yes, we know that modern notions on what is and isn't "underage" and "out of wedlock" aren't always like ones they had back then. That doesn't mean that you have to add at least one 14-year old girl who has a thing for knights to every chapter. (At least there weren't any actual sex scenes so far.)
Again, I'm just halfway through the 1st book, but I think that at least some of it could be read. If you pretend it's generic fantasyland AND tend to agree with at least some of the author's views. Not as a serious ISOT story.
ADD: Also, I'm not an expert on mindset of 30 years old Polish engineers brought up during the 70s, but whatever it was, Frankowski portrayed it wrong. Typically American attitudes with frequent, but vague mentions of "socialism," simply don't sound right.
ADD2: Oh, joy! Someone actually
weighted those "silver pennies" at least! And parchment is
definitely not like paper. But it's still as sloppy as Dan Brown at his worst, and Dan Brown at least has less political axes to grind.