I love the Baroque Trilogy. It's such a different universe than his other work, and I'm a history buff so it's fascinating to read and try to figure out what is accurate, and what is his imagination.
Ps: Anathem > Seveneves, unless you ignore the last third. Stephenson is usually weak at the end, when all the pieces are put in place and there is no room left for brilliant tangents. Anathem suffered surprisingly little, Seveneves more than usual.
Come to think, I have the same issue with Snow Crash and Heinlein's Starship Troopers. I remember both of them as nonstop action thrillrides and suppress the endless bloviating over linguistics and ethics, respectively.