Bests & Worsts Reviews from Amazon

I'm amazed at all the good reviews. i just replaced my 3M filter with one of these and there are perhaps 20 - 25% as many pleats in the material on these, meaning about 3/4 less surface area to filter with. The ad said "Comparable to 3M filtrate mpr 1500 to 1900 ultimate allergen defense" but not true/ accurate. i suggest you explore the actual surface area -as if the filter material were stretched out- prior to buying a filter. I surely wont buy these again.