I simply can't believe hearsay. Miele fans are known for thier fantastical claims. To hear many Miele fans tell it, thier machines vacuum by themselves while making no noise at all, washes thier car, feeds the dog, and rocks thier baby to sleep. I know Miele's filtration is Grade A Excellent but the sheer notion that they capture all dirt is simply an impossibility. Miele cannot suspend the laws of physics. Any porous surface will allow some dirt to pass through. If Miele's bags were perfect, there would be no need for further filtering media. Home Care Industries tests thier bags using real world and laboratory means. They are among the highest filtering bags on the market. Many other companies use thier bags branded to thier machines. I've never heard or seen with my own eyes an Electrolux/Aerus machine that was blowing dust. If that were the case, they would clog and be trashed like crazy. Aerus and Electrolux uprights are not "sealed" for sure but the Platinum canister is and has been proven beyond the shadow of doubt to be sealed. I'm sure the Platinum upright that will eventually come will be similar, they always are.