Yankee Hill products that I have experience with are very good. 35 db reduction is actually very good suppression for a 9mm suppressor especially since they indicate that this is a dry sound reduction. It would be safe to shoot with this suppressor without hearing protection. It would probably sound a little louder than a fully pumped up pellet gun.
I would say it is a good choice.
http://www.yankeehillmachine.com/store/cobra9mm.html