Highlight of part three for a logistocs geek like myself: Romans and Greeks had standardized ammunition, not just rocks that happened to lay around. That's how you build empires! And roads and aqueducts, of course...

EDIT: While the siege of Helm's Deep was perfectly done in the film, the Siege of Minas Tirith feels more like Holywood, very well done Hollywood but the difference between the two is deffinitely there.