I used this for collecting the dust while cutting plaster walls (old style lathe and plaster) in my living room. Without this collector I would have created a room full of dust. With it, only a small area right around the work area got dusty, and even that was not too bad.
One tip from my experience is to make the first plunge as fast as you safely can, because dust escapes before the shoe of the collector gets seated. After the shoe is seated, it is very effective.