Both huge and majestic, the Eldar war walkers moved and killed with a sense of grace, that only the sons and daughters of Asuryan possess.
As for the Eldar I have only this to say: Wraithknights.
The scenes of Boyz finishing wounded Space Marines, as well as the aformentioned Deff Dread tearing a Blood Raven in half, were quite intense. I simply love the fact that both the Eldar and Orks have been presented as a genuine threat.