I am skeptical that a particular brand of N95 mask is significantly more efficacious for a particular filtration milieu than others, beyond the N vs. P vs. surgical designation. I think it is mostly a matter of being able to claim testing in marketing. I guess we need a Consumer Reports lab to test and rate them. I am of the camp that anything you can do to reduce the viral load is desirable. If your full hazmat suit with coworkers to disinfect and help take down reduces the load by 100% , that's great, you're fortunate. If all the rest of us can attain is 80% over no protection at all, I'll take that.
https://www.hindawi.com/journals/av/2014/859090/
Above is a link to a paper on transmission of a flu virus. They use the term um (well , the u is the micro symbol) - so it is in micro-meters, or microns.
I was trying to find out how much of what is inhaled is a virus attached to a dust particle. I skimmed the paper but didn’t see that.
It does say though that a flu virus will have all sorts of different sizes (so maybe it is attached to dust?). Or perhaps droplets, vapor, etc. Anyway, they did experiments of the various sizes, and most of it was on the larger size. With a smaller percentage being the smaller ones that can get sucked deep into the lungs.
I think that was the paper that also talks about how you need a flu virus to reach a certain number of viruses in the air to be considered a large risk.
So bottom line as far as I can tell, anything you can do to limit exposure is helpful.