I like Greg Bear a lot, because he definitely doesn't forget the "science" in "science-fiction". Darwin's Radio/Darwin's Children was, in my opinion, spectacular (although if I remember correctly the first one is better than the second one). For some reason, though, I enjoy them when reading them, but I usually can't remember them that well afterwards - Blood Music and Eon/Eternity are a good illustration of that - I know I liked them, but I just can't remember what/who they were about.
I guess Slant will have the same "impact" - I liked it, I don't think it will stay in my memory for long. The basic idea is that, in a pretty near future, nanotechnology is... everywhere. In particular, it's used on a fair fraction of the people as "therapy" - to correct chemical imbalances that are the source of diverse "suboptimal" mental states. Oh, and this is also a future where AI can become self-aware.
But what happens when therapy begins to fail on a large scale, a secret society builds a gigantic complex (supposedly a cryogenic facility), and AIs are not built the way they should be built? That's what Greg Bear explores in Slant.
He does that through a hanful of characters, whose point of views we follow alternatively along the book. What the characters have in common is not clear at the beginning - and the fact that the end is kind of confusing makes the relationships not that obvious at the end.
The depicted future is pretty believable in my opinion, but the characters are forgettable and the plot is kind of messy. So it's one for the "not bad, but not great" category.