I have a number of Cobalt profiles and have been quite satisfied with the quality of them. My use purpose, which might well differ from the (more narrow) intended purpose which is to emulate, or copy a certain film or digital look, is to use them as a "finishing" application to give a project or sequence a consistent look to the images. I do not put importance as to whether that might be Kodachrome or Provia or Fuji. I've chosen, and added to my Favorites in LR Classic a selection of finishes from each of the cobalt profiles that I have purchased and will apply just one to a sequence of images. Initially I was disappointed by the Kodachrome profiles because in my mind they did not represent what I remembered of that emulsion. Now I just mentally discard the Kodachrome name and just use them when a sequence benefits from that particular look.