I should have known that you can't get "something for nothing". These filters have about half the filter material (number of folds) as the OE type I have been using. That's why they cost half as much. Obviously, they won't last as long or filter as well. My mistake. I haven't put one in the furnace yet so I can't speak to anything else about them.
Furnace filters may not be the most exciting buy in the world but any time I can save 50% I can live with that. So far I'm very happy with my purchase and will be back for more.