Just FWIW, I'm allergic to just about every inhalant there is, and I was a little worried about getting a bagless vac, but actually I've found it to be MUCH "safer." Yeah, there's a minute or two of emptying it, but you do that outside (and if you put the filter deep into your garbage bag during emptying, which you want to do anyway, hardly any dust escapes). There's definitely no "dust cloud" unless it's really windy AND you're being sloppy.
Every vacuum we've had with bags, even with the supposedly HEPA bags, just spewed dust all over the house after it was a year or two old, because there's always an unfiltered unwashable exhaust channel, plus the flexible bags just don't filter as well as a much thicker exhaust filter.