I got the Dust mask today. Once I got done with my painting project, I opened it up and read the instructions*. They were pretty well written and didn't sound like they were translated by a computer to another language.
Enough about the instructions... I put the mask on and waited for my glasses to fog. They never did. My breathing was only obstructed a little bit, maybe about 5%. Much better than the paper masks where it's around 60%. The mask was fairly comfortable, but did take some playing to get right.
With the mask on, I started the belt-sanding phase of my latest project. When I finally quit 2 1/2 hours later, my glasses still hadn't fogged, my breathing was normal, and I was covered with sanding dust. Who could ask for more?
I put everything away and then finally took the mask off. With the other dust masks, I had to take them off as soon as the tool stopped and wipe off my fogged glasses.
I'd recommend the dust-b-gone mask to anyone looking for a better dust mask. It seems pricey, but it's designed to last for several years. The manufacturer estimate 3-5 years with wearing it 8 hours a day. That's less than $7 a year. It's definitely an investment worth making.
*The reason men don't read instructions is because they're either poorly- written or just plain wrong, so we skip the headache of trying to understand bad instructions and just go to figuring out how the thing works anyway.Thanks to mac davis for the initial recommendation, and thanks to everyone else who responded to my initial query.
Puckdropper