The reference is to Wood magazine July 2017 (sorry no free link to that article). Using a Dylos and sanding MDF panels they tested 8 Units 5 bag and 3 canister DCs. All the bag units outperformed the Jet and Powermatic canister units (which were rated fair). The winner was the Jet 5M bag followed by the General International canister. All the other bag units were in between (most of which were rated excellent). Most of the discussion about this that I have seen, seems contrary to what would be expected.
Where the tests fall short is when they acknowledged all the machines had leaks, they could not see but could feel. So they used silicone, duct tape and foam to seal the leaks. What this tells me, as with any DC system, performance is only as good as the sealing of the system. Shame on the manufacturers for allowing such wide variations occur in build quality to have a good filtration system spew dust through cracks from poor designs. Part of the problem is they are working backwards on the design. Adapting a 20+ year old DC blower design and adding current day fine filtration without better sealing and or connection methods or surfaces.
So in this case they are measuring >0.5 micron (smaller than all filters) and have you believe that a Jet 5 micron bag will outperform every other bag or canister that is 1-2.5 micron. So there are two conclusions I came up with. That a Jet 5 micron bag and the GI 1 micron canister (both performed similarly) can filter 8x more small particulate than the Jet/PM 2 micron canister (both performed the worst). Or the test method was highly unscientific and is not repeatable assembling and testing the same units again.
What the article did show that was interesting, was how a standard single stage DC with 4" flex performs with a clean (seasoned) and dirty filter - or for many, typical use. Only the Shop fox produced over 400CFM with a clean filter, and only the JET/PM canister units produced over 300CFM after sanding 76sq ft of MDF. All others were in the mid 200 range with the GI at 176CFM. So most of the 1.5HP 1100CFM+ DCs with a seasoned, clean filter and a 4" flex hose, typically only pull mid 300 CFM.
For Wood magazine, these are difficult tests (with such poor designs) and can only do so much. I appreciate what tests they do, but have to add some real world understanding into the mix as well.
Hope that helps.