Barry, that review was a few years ago, I think HEPA filters are available on many brands now.
I would worry especially about what you encounter flipping houses, probably sanding some pretty nasty stuff (lead paint, etc).
My dad died of lung cancer. His final weeks were complete agony, not clear whether his lungs would give out first or his heart. He was always a dignified man, but in the last week he was begging for someone to kill him.
I think of that when I make safety choices.