I have tried both on my cd transport, audiomeca mephisto II. First I used the daruma and was amazed at the improvement over no suspension (and this with a very elaborate homemade stand - sand filled plinthes and carbon block supports). Even my wife thought they were great and she generally thinks I'm crazy. I then tried the rollerblocks with tungsten, but I was worried about the soft material my cd player is made from so I used the metal plates. This was not as open and as 'good' as the darumas - though it was a brief listen. I then went to inverting the symposium and resting the balls on one of their svelte platforms and this seemed the best. It was however an expensive change vs the darumas. It is best to test each however and some companies or shops will let you try them. Hope this is of some help. If you have questions drop me a note
Gary
Gary