Product review (5 stars): Quiet, efficient disposer, equivalent to ISE Evolution Essential
The KitchenAid Superba is manufactured by the same company, Emerson Electric, as makes InSinkErator brand disposers.  Its specs are the same as the InSinkErator Evolution Essential disposer, and installation is the same.  I was able to purchase the Superba for less than the Evolution Essential.  Having installed and used InSinkErator Evolution-series disposers before, I expected quiet, strong performance, and the KitchenAid Suberba did not disappoint.  It grinds waste thoroughly and vibration of the sink is dampened by its design.  If you're looking to upgrade an older disposer, particularly from some of the lower end Waste King or ISE Badger disposers, you will will be amazed at how quiet and efficient this model is at grinding waste.  It is bulkier than those models, however, so be prepared to sacrifice a little space under the sink.