I've got the "Flying Saucer" for mine. They love it. So far the only issue has been that while the saucer itself is silent, the whole cage rattles when they use it. I have the Chinchilla Mansion from Quality Cage, I think it's mostly the urine guards that rattle. Oh, another issue

When I got my chins, one turned out pregnant. I think it's recommended to remove the saucer for babies, but it was pretty hysterical seeing the baby trying to use it. Especially when he jumped on it when mom already had it spinning! He learned it real quick. And yes, dad and son are neutered now, they all live in one happy family group.