Starting with the least egregious first: I have to say is that Dawkins' editors (across all the editions) definitely did not do their job, if they even tried to in the first place. There are areas where the book does nothing but repeat the same sentence over and over in consecutive lines, and it's like no one noticed that he wrote the same thing. I was starting to feel déjà vu when reading it out loud to my partner, and it was really pissing me off.
Next, his examples are almost entirely hypothetical, and I do not care if something is "mathematically sound." Does it actually work that way? Should I really be thinking of it in that framework? In a lot of parts, I really get the feeling that I shouldn't be and like he tried his best to tip-toe around the things he "shouldn't say but really wants to." Not to mention that at some point, in the update to the 40th edition, he tries to prove a point using hypothetical seaweed! Like, certainly there has to be something real that he could discuss. If not, he shouldn't present his thoughts or assumptions as fact.
It's an... incredibly sexist book that tip-toes around white supremacist structures. It's no wonder that so many dudes on red pill podcasts still really like this book (especially since I remember pre-red-pill that a lot of cis men loved this book, and it really became a red flag of sorts).
Tied to that, he really loves to go after either easy conservative critics of his book or people who actually have legitimate criticisms of his work (which he treats with contempt rather than really addressing them in a useful manner). For the former, it's because he made his name going after easy fundamentalist targets... so he's keeping his normal brand. For the latter, it's because he can't stand being told he's wrong or that he's misinterpreted something in a field he's not a part of (usually anthropology). This is hilarious because, in the epilogue to the 40th anniversary edition, he claims that scientists can at least be told they're wrong (unlike politicians). This is hilarious because my entire experience of scientists (and honestly, academics or high-level researchers) has been that they... can't handle people disproving them. We often get stuck with incorrect science for decades because of this! It's amazing that he'd ever say it, but it's not surprising because... that's literally him.
There was at least one really funny moment that felt very out of place. We were reading all of the footnotes as we went. Many of these were far too long and should've never been allowed to be a footnote, which is another reason why I think his editors didn't do shit to actually make the book coherent. Like seriously, there was one footnote that was roughly five pages and entirely about penises for some reason that I cannot remember and did not feel relevant to the conversation at hand, and there were many others to correct things that didn't need to be corrected, like to account for updates to a series of novels that he referenced that wouldn't have changed the point he was making. But the best one was him complaining about computer viruses and programmers who make them and just... what the fuck. It was so out of left field that, as I was reading it, I thought I'd lost my mind.
This book is rubbish. Whatever useful information anyone has gleaned from it, we don't need this. It's truly an excessively verbose piece of nonsense written by one of the most pompous men in his field.