Finished this last night, and to me it is certainly one of his weaker books. It's a thriller where nothing truly thrilling really happens, and feels like a clone of DVC. However its strengths lie in its ideas, which whilst far fetched at first were really well developed and truly fascinating. The last 20 or so pages, after the "final showdown" got me thinking more than his other works.
Spoilers:
Whilst in terms of action and being a page turner, it is not as strong as his previous works but the final segments more than make up for it. Everything comes full circle, making perfect sense and the revelation of all this masonic symbology hidden blatantly throughout the washington mall was astonishing.
It will surely make a terrible movie.
7/10.