Some 3M respirator filters are way easier to breathe through than others. 3M won't tell you which ones, so I tested them to find out.
Based on the breathability results, I'm going to go with the 2291 Advanced P100s or the 2071 P95s when I need particulate filtration for a 3M bayonet filter respirator.
You can get more breathability by targeting the contaminantes you need to filter instead of arbitrarily wearing the most everything filter you can get.
But, don't compromise on the protection you need. Sometimes you may need a combo filter for protection from multiple contaminants.