K&N filters are a high quality unit but cannot be considered a high efficiency filter based on the beta ratio info I have seen on several part numbers. Their filtering efficiency is between the average filters and the high efficiency ones. Better than average,but only just. If you read their advertising info, they emphasize flow, so if you want a well constructed filter that will not go into bypass (on cold starts or high rpms) and have a long OCI capability, it's a good choice.
Of the brands you mentioned, the M-1 is a more efficient filter, on average, than a K&N or a Wix. Remember filtering efficiency sometimes changes between part numbers within a brand. Wix is usually only slightly above OEM efficiency but well constructed. If you want efficiency, go with the M-1.
You don't get a huge indication from a UOA on filtering efficiency unless you have a bypass system installed. The spectrographic analyzer only "sees" particles under five microns and that's below the filtering threshold of most filters. They may catch some in that range, perhaps enough to effect the number, but usually only slightly. In order to evaluate filter performance, you need to do before and after particle counts, I.E. run 5K miles on filter A, do a particle count, then run 5K on the better filter B with fresh oil and compare the results.
"Insolubles," as Blackstone lists, includes everything, including carbon, oxidation byproducts, large chunks of metal, additive fallout and anything else. I don't think it's an accurate enough tool to make any usefully graduated evaluations on filter efficiency. It can say "OK" or "Not OK" but I don't think it can tell the difference between two filters that aren't just light years apart in efficiency.