Anathem was my favorite book by him. It has a lotta re-read value, I appreciate the work he did to make it feel like a complete, fleshed out world. But different folks have different tastes, and that's ok.
I also liked Seveneves, but it should have ended 2/3 of the way through. There was a point that would have made for an excellent ending (which is something Stephenson famously struggles with IMO), but then he forced in another 1/3 of a book that didn't engage me and which felt like it just petered out.
Anathem and Seveneves are my favorites of his, in that order. The orbital launch and operation in Anathem is probably my favorite piece of writing ever.
For me it was the juxtaposition of apparently realistic descriptions of orbital mechanics with the half-arsed handwavy gibberish about biology.
Maybe it's because I know more about life sciences than physics and simply missed that the orbital bits were equally nonsensical, but at least they didn't manage to shatter by suspension of disbelief. But then some vague magical genetics and a brief mention of "yeah, they can eat algae" are used to solve a bunch of intractable problems - and both treated as being far less interesting than, as you say, pykrete!
Given the title of the book and the fact that the final third hinges on the biological bits, it felt incredibly lop-sided - like he'd spent all his research time playing with Kerbal Space Program and only got round to stitching the two parts of the book together on the night before the deadline.
The biology stuff seemed far-fetched but plausible-ish, which was kind of how I saw the physics bits: sure, that might work given infinite tensile strength metals.
And sociology / anthropology / linguistics? Eh, we can wedge some stuff in once the important parts are done.
I didn’t hate the book at all. It was otherwise fun to read. But man, those bits I mentioned really stuck in my head and I couldn’t un-see them once I started noticing. Like, imagine that literally every time you were in a bar or restaurant with TVs, at least one of them was showing a documentary of the American revolution. Wouldn’t that be odd? Well, apparently in 7000 AD people just can’t get enough of their own founding history lessons.
I also liked Seveneves, but it should have ended 2/3 of the way through. There was a point that would have made for an excellent ending (which is something Stephenson famously struggles with IMO), but then he forced in another 1/3 of a book that didn't engage me and which felt like it just petered out.