Shakespeare is meant to be seen, not read. This was more clear than ever to me with Coriolanus. While I like to say I understand Shakespeare well when I read it, the action and visual with it just makes it so much better, so much clearer.
Overall, I recommend this movie. There are moments about which I am unsure but as a whole, it's a compelling and pointedly well-acted movie. I was universally impressed by the performances, with Vanessa Redgrave's standing out even above the rest.
I'm not familiar with the original play, beyond a few lines here and there, but still found the plot and motivations easy to follow. If you are the kind of viewer who requires a purely good, easy to cheer for character, this may not be the film for you. While every character had a logical motivation, it was hard to wish for one to succeed over the others.
The citizens of Rome are certainly not shown in a great light, but then, neither are the soldiers. Every character wants what is best for him or herself under the guise of what is best for everyone--but not one character (save perhaps Brian Cox's Menenius) is able to consider what is truly best for all. The citizens, demanding their share, cannot accept a leader who does not respect their needs. Coriolanus thought the citizens well below him, which is not exactly an admirable trait in a leader.
This story is rich with political intrigue and questionable themes, but even then I can see why it's not one of Shakespeare's more well-known stories. Some of its characters are rather shallowly drawn and not a single one is purely likeable.
I must question one decision. Without spoiling a 400+ year-old story, I have to say that the last shot (not the last scene, but the final shot itself) was an odd choice. The end was clear in the second-to-last shot, which was framed much more memorably and beautifully than the last. And perhaps the choice to end with an awkward shot was meant to have a deeper meaning, but I still have to question it. The pentultimate shot was, in my opinion, a much better ending.
Still, Fiennes' modern twist to an old Roman story grounds it in an interesting way, and as I said the performances are universally riveting. It's not a movie for everyone, but it's certainly one that's well done.