[BarbaryCoast]

Most of this guy's questions could have been answered by reading the very Wikipedia article he cites. For example, "a HEPA air filter must remove—from the air that passes through—at least 99.95% (ISO, European Standard) or 99.97% (ASME, U.S. DOE) of particles whose diameter is equal to 0.3 μm". So, yes the H13 filter meets this spec (99.95%), and the E12 does not. If he didn't trust the Wikipedia authors, he could always follow their references to check for himself.

The question of whether H13 vs E12 actually matters is likely to depend on application and environment. Providing factual information, perhaps taking the position that the IKEA filter is "good enough" despite the review, would have been welcome. Then each reader can evaluate all those factors for themselves.

Whenever I checked his quotes from The Wirecutter, I found that WC had it right, and blogger had it wrong. I stopped reading in detail after the first two sections, then just skimmed the rest.