Excerpt: Our previous batch feed Insinkerator (20 yrs old est'd) died and I wasn't going to even bother getting a new one. After speaking to a helpful ABT rep, I changed my mind but decided to choose a 'continuous' feed one. I was assured that their installation crew could easily install an on/off switch (batch feeds work when the cover is turned). I was absolutely shocked at how quiet it was and how quickly and efficiently it works.
Summary: VERY quiet...and that's the maint reason I replaced my old Insinkerator 777. The KitchenAid does have a little low frequency vibration(I think they all have some)...but it's negligible. I researched this purchase on Consumer Reports. This unit was the best rating combination of quiet, effective, and low price. Would have given it five stars if were better balanced...but I'd buy the same model again...REALLY quiet!
Summary: Quiet, powerful -- we love this. We've had no problems with this after a year of use. It is so quiet -- we have an open kitchen, and we can run this without disturbing conversation. If people notice the sound, they think it's the dishwasher -- amazing! Be aware that it is really large. Our house was built in the 1950s, and the pipe for outgoing water from the sink drain is maybe a foot higher than the floor.
Summary: We are very happy with this disposal. I selected this after reading the Consumer Reports review. It's incredibly quiet and has been effective with normal food. We haven't tried anything too tough with it, but it seems to do a great job with daily use.