I missed the question before. It has a different, and dare I say it, more fluid impact. It can impart both more force but less trauma on the part being hit. I have no idea if it's quieter, but logic says it must be. These tools aren't loud so I don't imaging anyone cares. This isn't a 1/2" oogga-doogga impact.
I'm still lusting for this but best I can find is just over $180 on eBay, so nah.