Just bought a 1999 Terry 725R, when the previous owner was demonstrating its features he said "It has a bathroom fan" as he clicked the button, the fan blade shattered. "I mean, it HAD a bathroom fan....
Add a variable speed switch and the Vortex can be just as quiet as any of them. It is loud when it's running full tilt, but it moves lots of air when running slower too. I'm very happy with mine.