A few things to say - one, the characters are not nearly as compelling as the ones in Anna Karenina. Curiously, the most exciting personage in the book is actually Napoleon, who is genuinely fascinating and brilliantly drawn. The ostensible heroes, Prince Andrei and Pierre Bezukhov are ok, somewhat interesting, but somehow not fully accessible. The heroines are mostly just irritating - especially Natasha, who is almost unbearable. I did actually really like Andrei's first wife, who was never mentioned without reference to her moustache (!), but she didn't get much airtime, unfortunately. But in any case, as far as social drama goes, the novel is kind of a failure.
What is really curious to me is that while the characters are generally kind of noble, lofty personages, the Afterword kind of knocks them off their pedestals. Marriage seems to turn them into crabby, petty, self-centered, uninteresting people. It's a depressingly accurate portrayal, actually, but it's sort of jarring. It also reminds you that Tolstoy is a genius. After all these completely bland dramas between largely flat and uninteresting characters, suddenly you're plunged into completely mundane everyday life and you're reading it like holy shit this is so well written. Why oh why isn't the whole novel - the "peace" parts I mean - like that?
The portrayal of war, however, is thrilling. And while the concluding essay on the philosophy of history at the end of the book is pretty dull, the reflections on history sprinkled throughout the novel are fascinating. Overall, it's what makes the book a masterpiece - it is jaw-droppingly incredible. It is so detailed and well researched and yet so vividly alive, both giving you the feel of actually being there AND the bird's eye view AND theoretical reflection on why things happen the way they do - it is just mind-blowing. That, my friends, is why the book is a classic. Is it a must-read? Not really. I mean, if you have the time, it's worth doing, and maybe you could kind of skim large portions of it, but I suspect there may be other, equally rewarding portrayals of Napoleonic war, so if you're gonna go Tolstoy, do a different one.