This is a great filter kit for anyone doing portraits or people video. The CPL, ND, and black mist filters are all quick to swap out thanks to the magnents and the quality of the filters is pretty solid. I haven't noticed a detriment to my image sharpness with these but I also am not using them on a high megapixel count camera (20-24MP for me). The best two parts are the case that these come in - it opens like an accordion file making it super easy to find and grab your filter and the lens cap meaning I can leave my magnetic attachment on all the time and still have the benefits a lens cap offers when my lens isn't in use.
Nitpicks are that the ND filter requires screwing on which isn't the easiest - I definitely have scratches on the magnet base from not aligning everything just right and trying to screw it on. If you don't get it screwed on just right then the ND filter is a pain to adjust since the magnets attaching the second CPL are strong enough to turn the first CPL when it isn't screwed in.
But for the convenience of quickly adding and removing an ND filters for something like a wedding where you go from outdoor video to dark inside video in minutes make this a fantastic addition to my video kit. Well done K&F!