I found the model (GFC520V) recommended on line. As it is a newer model I thought it would be quieter than my old model (GFC520F). After installation I did not notice it any quieter than the old one. Chops food well, as the old one did too. I had hoped from some improvement over old one and was disappointed there. But it does do the job as well as the old one did. So I guess I can't complain.
This was the disposal model that came with our house but, after ten years of raising boys and all the stuff they try to shove down the drain, it wore out. I was very please with the way the last one worked and wanted to keep the same model.