On a whole, I found Brisingr to be a much smoother, richer, more thoughtful book than the first two in the series, Eragon and Eldest. Paolini's writing becomes more subtle with each book, and you can definitely see him growing from a talented adolescent into a gifted adult writer.
In fact, the only thing I didn't particularly like about Brisingr is something it can't help: it's a middle book. As such, it doesn't have a definite conclusion, but keeps leading up to things that will happen in the final book.
For those who found out about Eragon's parentage Eldest and thought it was too much of a Star Wars rip-off, I say this: new information comes to light in this book. Read it.