nickel plating is a big problem with AC related products. Most companies use it to just add a bright non tarnish finish. The quality of the plate and how it sounds are not a consideration. I offer a silver plated fuse holder, so have a bias toward believing in these small improvements. Here is something you can try. Sand off the nickel plating on a fuse, clean it and coat it with a contact enhancer and see if you can hear less brightness or sheen to the playback system.
