The stock magnet holder is very rigid and transmits vibration. For the most part if your glass is nearer the maximum rating of the magholder and the rubber feet are on, it isn't much of a problem, but on glass less than 1/2" thick it can be fairly annoying. Noise is a difficult issue because it is subjective, some people can't hear as well or aren't bothered by noise, others are extremely sensitive to noise. The silence holder sticks out into the tank another 3/4". It almost completely eliminates noise. The 6065.510 clamp will get an update in the next couple weeks that will have a rubber sleeve between the pump and clamp, this won't stick out any further and will cut the noise in half, not as silent as the silence holder but still a big improvement.