This is a must-have for anything doing nested ESXi. Seriously. I spent a good amount of time researching exactly what was going on with the shadow copies / CPU use and why it was happening, and causing our network/cpu load to be brutal. After installing the mac learning dvfilter, all of the unnecessary traffic and CPU overhead vanished, making a complex nested environment feasible.
This is especially important when using NFS datastores on your nested ESXi servers!
Thanks for this, Christian.