I've just read it, and it was reading it that I sort of confirmed my theory, as more and more facts I wasn't aware of that he pointed out fit it perfectly. but it's not like a significant change in doctrine, it's just a different way of understanding big capital: it has *always* been feudal, in the sense that it doesn't really produce anything, it's just rent extraction in disguise. capitalism was born and defended on rent-free grounds, but it had the seeds for regrowth of feudalism at its very top from the beginning, because the prototypical big capitalists, those who only invest and extract and reinvest capital (contrasting with the small capitalists, that need to work in their own small businesses and get exploited by the big ones about as much as other workers) are essentially feudal lords in at least some aspects of their power and rent extraction.
so I've come to the conclusion that feudalism fought back and swallowed capitalism, and lenin describes how that happened for the first time. now I need to study later history to understand how anti-trust law and regulations came to be and to restore some competition for a few decades after WWII, but then feudalism swallowed capitalism all over again. I'm not sure whether it's cyclic (it could be one of the economic cycles that marx wrote about), or a structure that feudal lords could consider retaining indefinitely like soldier boots on our faces forever, but... (TBC)