Well, it's a Neal Stephenson book, so you know a few things before you start reading:
1) It's long
2) It will contain some memorable passage you will quote to friend and foe alike
3) It's populated by characters that possess some sort of motivation, that may or may not make sense to you, but is internally consistent
4) It contains incredibly action action scenes
5) It will make you think about a thing or two. Or two hundred.
6) It's better than 99% of the other books that were published around the same date.
7) The ending.... oh, the ending.
So, all that is true. Is it as good as Anathem? Or as Cryptonomicon? Yes and no.
The author sure seems to have spent a lot of time doing plot. There is a lot of it. Other authors would live 5 or 10 years on this amount of plot.
As a Dumas-pére action-packed romp, it's kickass. As a novel full of deep ideas... nah, not this one. For that, get Anathem. It is, however, a page turner, a ton of fun, and yes, really, really good.
I recommend it to pretty much anyone over 14, since it contains some stuff that may be a bit too direct for younger readers.