I say avoid it at all costs, especially if you have hypersensitive hearing like I do. This breed of vacuums sounds as loud and fast as a woodworking router (approx. speed: 25K-30K RPM).
I'm not avoiding it. I love the vacuum, and my dad says it's a somewhat quiet vacuum, not too loud. I use the Windtunnel to clean it out because the Windtunnel is a bagged vacuum, and the Bissell is a cheaper alternative.