The basic plot of this book is Darcy & Elizabeth are traveling in week before xmas, he invites her family to Pemberley as a welcoming surprise to cheer her up (she is pregnant after 2 miscarriages) and D&E get stuck in an inn due to weather. Many uninvited guests, both old ones from P&P and new ones (even an American) also show up at Pemberley. Romance,drama, and conflict ensue. D&E eventually do arrive @ Pemberley, where there is more joy, romance, conflict, and finally happy endings for all.
(Did not want to give away major plot points).
My conclusion is that Darcy and Elizabeth were the least interesting characters in this book, with the least interesting plotline. I especially did not need to know, on at least two instances in 1st 60 pages and # of times afterwards, the state of Darcy's, ahem, "manhood" (the book's term), that they want to sneak off and do it whenever possible, that they made love twice on Christmas night, etc. I am no prude, but this is not what one expects in an Austen-ish novel, even a sequel. Other characters lust, too, but not like D & E.
D & E's interactions, conversations, etc. reminded me of the constant "I will always love you" "Without you I am nothing" "I need your kiss" "I will protect you forever" drivel that you see between Edward & Bella in the Twilight series. My favorite characters in this book actually were Kitty and Anne de Bourgh, each of whom had a plotline as least as important as was given D&E. Georgiana and Col. Fitzwilliam also are given major prominence in the plot.
Mercifully, although Mr. Collins was present in book the author gave him no actual words to say--I would have wanted to hear him, but only if Austen provided the words. Many chars (even Mrs. Bennet) showed some type of growth/personality change/life change, etc. As noted above, 80% of what Darcy and Elizabeth did was lust after each other for much of the book.
Lizzie did have one major interesting event in 1st half of book and in 2nd half played peacemaker amongst the cast of 20+ characters staying @ Pemberley (even making nice with Lady C , who actually made nice back).
It was an interesting story overall and the author did a decent job juggling about 8 different plotlines and interweaving many historical events, inventions, etc., from the 1815 time period (in which book was set). I wish author had saw it fit to have her characters speak, if not Austenian language, period-appropriate language (although she did lift quite a number of P&P descriptive passages word for word). I do not believe that men & women in JA's time would have used expressions like "Scream your head off" or "For this next phase of our relationship".
I do agree with the other Amazon reviewer of this book who noted that every character speaks "huskily" or "rasps" at some point (usually while in a romantic moment with another). This author seemingly had only a few basic adverbs she seemed to use repeatedly. Very surpised to read in bio that she is an English teacher.