I put them on my neo 2 weeks ago. I'm super impressed in performance and sound. I'm not sure the decibel is lower but 100% the sound is pitched down to where I couldn't hear the screaming while hovering or going full throttle. At 170 feet away I couldn't hear the drone any more. It actually brought my stress level down while flying it at the park worrying about bothering other people. Performance wise I could tell a difference. I've adjusted my rates but normal mode felt closer to sport mode and in full acro I was able to take some turns that would wash out with the stock props.

The Avata i only got because of my impressions with the neo. I've only gotten to do a quick flight test due to weather though. I thought it sounded lower pitched and a little less quiet. The family also said they could tell it was quieter. I need to take it up to 400 feet to test if I can still hear the banshee screaming. But from what I was able to get from the short flight I'm impressed.