I got my Gill Mask a couple weeks ago. I did my research and was looking for a respirator that might offer all day comfort while not costing a ton in consumables. I carefully chose the surgical masks that I would use as filters for ones that offered a combination of performance and breathability. So far so good. The Gill Mask itself is fairly comfortable and, once adjusted, fits snuggly to give a good seal. I feel confident when wearing it that I and the people around me are protected.
There are a couple things that I am continuing to tweak however. While I got a regular, the mask is a little big for me. I wear glasses, and the nosepiece of the mask comes up a bit high on my nose. I have tried putting on the mask first and then the glasses. This results in the glasses sitting a little further from my face and not working quite right. I have positioned the mask lower on my face so the glasses sit right. Now the lower end is below my chin. It seals fine, but the bone of my chin touches the plastic structure of the mask and may not be comfortable in the long run. If a slightly smaller version were available, these problems might be solved.
Second, the straps must be adjusted fairly tight to hold the seal, Not a big deal, but the strap material is fairly stretchy and I have to pull on it quite a bit. I may replace them with something else to make the adjustment quicker and easier.
So, overall I am happy, but buyers should expect to do some tweaking to make it work for their face and head.