I have read a lot of Austen fan-fiction, especially Pride and Prejudice sequels, but this series is probably the best one I have read- note that I say series, not book. This isn't my favourite of the series, but it acts as a really good introduction to the later books, although they can easily be read as stand-alone books. Elizabeth Aston's series probably works so well as a P&P sequel because it doesn't actually include Elizabeth and Darcy, as they are off page, cavorting off to Constantinople on a diplomatic mission. This way, there is no chance that their characters can be butchered by well-meaning writers.
So, 21 years after Pride and Prejudice, Darcy and Elizabeth are off on a diplomatic mission to Constantinople, leaving their five daughters in the care of Colonel Fitzwilliam and his wife, Fanny, in London. Poor Mr. Darcy, having seen all the trouble that five daughters caused Mr. Bennet, only to go and have five himself. And all attractive, especially when you factor in their dowries of fifty thousand apiece. So it's not long at all before they all are the subject of gossip in London. There's Letitia, the most beautiful, but also prudish, and increasingly evangelical, and Camilla, too witty, just like her mother, and a bluestocking. Then the twins, Georgina and Belle, or Night and Day, who drive all the men wild, and finally Alethea, the musical prodigy, still in the schoolroom, but she's acting so innocent that she must be up to no good. Camilla is the primary POV character, and probably the most level headed of the sisters, and definitely the most deserving in terms of her love life. I did think that her relationship with her eventual husband needed a bit more development, as by the last third of the book there is so much going on with the other sisters that it looses focus a bit, but at the same time, I am all like yay, wuv and marriage.
Some of the characters that were in the original pride and prejudice are present in the book, altered with varying degrees of artistic license being employed. Lydia is back and remarried after Wickham's death, which means that he is preserved as Lydia's "dear Wickham", while Lydia is now wealthy, extravagant, and a terrible influence upon some of the Darcy girls, all of which I think is fantastically done. On the other end of the scale is Colonel Fitzwilliam, who has left the Military for a political career, which of course comes with a free personality transplant. For someone with a supposedly happy marriage, he is such a grumpy git. Of course, the daughters are all slight modifications of the original Bennet sisters, but it feels to me more like an homage rather than a blatant copy, and anyway, who am I to doubt the power of genetics. Mrs Bennet and Lydia were silly beyond all belief, so, once out of reach of Darcy's influence, I don't see why some of their relatives shouldn't be silly too.
If you oversimplify the plot then it does correlate a lot to P&P, but the difference is in the details, and so there's enough difference to keep me happy. The viewpoints switched around quite a lot, but Camilla remained the focus, at least from the viewpoint. But the other viewpoints that are dotted around the book do help to keep interest in the plot up, and do help you to get to know some of the background characters a lot better (and helping to show some motivations, because else a lot of their actions wouldn't make sense).
A nice bit of Austen-fan-fiction, obviously not a patch on the original Pride and Prejudice, but its good enough to hold its own. 6.5?