I was skeptical but it works!
I bought this to use with my "acoustic" Celtic band. Lots of instruments with open mics and pickups of varying quality. I'm an old-school person when it comes to managing feedback thinking you should be able to manage with a 31 band EQ but I had become increasingly frustrating trying to eliminate feedback while mixing from the stage while also performing. I finally bought this unit and it worked flawlessly. I could hear a few frequencies on the edge of feedback during soundcheck but once the unit was activated there was no feedback for the entire gig. In fact, I'm going to have to adjust my gain structure because I had more gain available than ever before. FYI: I put this in the signal chain between my mixer and the powered PA which is a Harbinger MuV MLS800 Line Array PA System used in noisy pubs. No monitors were used.
RonDrum
Noblesville (Indy area), Indiana