In my experience that is mainly when dealing with Diamond vs cbn plated steel that will be used with a power tool and doesn't apply to slower grinding methods like hand sharpening (i.e. Atoma, DMT, or WEPS diamond stones). I have a WEPS and the diamond stones are one of my favorite. All this being said, while I haven't found any CBN lapping film, I have found SiC lapping film (from "Tools for working wood" which is listed as being used for getting p"scary sharp" edge) and it works great. I have had excellent results with this lapping film vs. Lee valley's diamond film (and yes, I've tried both). Hope this helps.