Okay, before I start, I want to say that this is purely my personal opinion, so don’t get offended, any of you Dan Brown fans out there.
In my humble opinion, Angels and Demons is far better crafted, as a novel, than the hallowed Da Vinci Code. The plot is structured in a much better way, the characterisations are far better than the pale ones created in DVC, and the tension is far more palpable in this novel.
In the Da Vinci Code, Dan Brown wasn’t able to bring Robert Langdon to life. The descriptions were so weak that one couldn’t even form mental images of the key characters. Not so with A&D. The characters are solid, more flesh and blood. One understands the persona of Langdon far better after having read A&D.
Further, in terms the underlying menace (that builds the suspense, of course), the Illuminati are a more credible enemy than Opus Dei.
Then again, in terms of empathy, one relates more deeply to A&D than the DVC. The latter is focussed purely on a religious angle. On the contrary, in A&D, the clash between Science and Religion makes the story more thought-provoking.
Bottom line: Angels and Demons is a fascinating book. In fact, if you pit it against everything else that Dan Brown has written, it is definitely his best.