I'm not sure I agree with you about Dumas treatment of women. I think the flaw with his characterisation for me, is that all the characters (not just the woman) tend to be one- or two-dimensional, in that I felt he describes their main positive and main negative aspect of their personality and then leaves it at that. I'm not sure I've exactly described what I mean here, so I hope it makes sense. But from that, with regards to the female characters, I feel as though he did try to cover a wide range of personalities, but is limited by the society at the time.
My reading experience is a lot different from yours, Andy, because I have very little knowledge of this period of history, and most of it would come from watching entertainment films set in this era, which can't be a true reflection, no matter how well researched. However, my approach to the book was that it was primarily for entertainment, so I was happy to overlook any factual inaccuracies (if I even know about them).
It was only after finishing the book that I found out it was originally written as a serialisation, which in retrospect, makes the format of the work more successful, in that it achieves enough action in each chapter, and if not always ending with a cliff hanger, at least leaving the reader wanting more.