I have a bunch of hydroton left over from a previous hydroponics project and have recently considered using them for my cacti and succulents. I like how they look, used as a top-dressing, and I think they could be beneficial mixed into the substrate for some plants. I might do a test and plant one cacti into my normal mix and another of the same species, in a new mix using hydroton and see if it makes any noticeable difference.
