I use them every day
And Slumpy’s “studio” molds are bisque ware, FYI.
Sometimes it’s trial and error, but if you know what makes a good mold and aren’t scared of drilling, they are a great option. Many more choices. As a ceramic and glass studio, I often get a case of 12 plates to drill as molds for less than one bullseye mold. That said, I also have a large number of stainless and slump-only molds as well, to fill all of my needs.