another link:
http://ecotechtalk.org/threads/9/
What excites me is that I can replace only the drivers on my mp10 and achieve the massive reduction in noise.
"QuietDrive is a new driver technology that will make the dry side motor run smoother and up to 90% more quiet. The way they do this is by efficiently minimizing torque ripple, thereby making the motor run more quiet. The good news is, previously released MP10, MP40 and MP60 VorTech models can run silently as well with just a QuietDrive controller upgrade."
I currently only do a slow ramp up/down on both my pumps since any more chaotic changes result in much more noise. I'd love to be using the other modes.