@mommyofhandk Personally, I find them easier to wear than lesser masks because they have actual structure and stand up on their own–there’s no tendency to inhale them like happens with cloth or surgical masks.
There is a slight resistance to breathing, the best way I can describe it is that I feel like I’m something like 1,000’ higher than I really am–for most situations, a non-issue. I have worn them when over 10,000’ and ascending (and carrying 25 pounds of stuff on my back.)