The authors have stuck to their guns, but have reiterated arguments that their critics are likely to find unconvincing. And that’s somewhat surprising; it should have been possible for them to accept at least a few of the criticisms and indicate further work was under way that would handle them.
I am curious to find out what the facts are, here. I’d be stunned to learn that DNA’s chemistry works with arsenic as well as phosphorus, or that both forms can code for the same amino acids. But stunning me is what science is all about.