I ran them in my last rear tire. No vibration or any of the symptoms you would get with an out of balance tire. And, when I broke the tire down, there was no rubber "dust" or any damage to the inside of the tire from the beads rolling around in there. Also, the ceramic beads looked like new.
I did not notice any longer life out of the tire running beads (as some have claimed) than with the life of any other tire.
I went back to conventional balancing on the tire I am running now, simply because I didn't have any beads on hand when I did the tire change.
I have maybe 3000 miles left on this tire, and when I change it...and the front...I plan on going back to the beads.
They seem to maintain the balance throughout the life of the tire where with weights, the balance will change as the tire wears.
Just my opinion & observation.