I watched this movie on Blu-ray two weeks ago, and find that I'm still thinking about it. Kiera Knightly is perfectly cast as the complex Duchess of Devonshire, who lived in the latter part of the eighteenth century.
The film follows most of the Duchess's life from the time she was married to the aloof Duke. The film perfectly shows just what a charismatic and remarkable woman she was, and how she coped with living in a loveless marriage and having to accommodate having her husband's lover living in the same house.
Living in a time when women didn't even have the vote, she used her charisma and beauty to great effect in the politics of the day, and managed to combine this with a great love for her children, while trapped in her private life by a cruel and despising husband.
During the film you root for Georgiana, hoping that she will find some kind of love and lasting happiness.
This was a beautiful film, the sumptuous costumes and photography just sublime. In fact I can't find anything wrong with it. That said, Kiera Knightley, stole the show. Can't say I was a huge fan of hers until seeing this, but in my opinion the film wouldn't have been the same with a different actress, and I think it is her finest performance to date.
As for the Blu-ray edition, well the quality is faultless, and I would say it is well worth paying the extra in order to do the film justice.
Buy this to enjoy again and again.