Review (4/5): works well, but has a minor design flaw
I have used ionizing brushes for over 30 years—since they were first sold by Sharper Image. The negative ions work very well to flatten the surface of the cuticle of each hair, making the hair less likely to break or split, and also softer.
This particular brush works well, but the one I received has a minor design flaw: the brush part pops off so easily that I have to hold it tight with my thumb, making it less ergonomic than it might be... not an issue for me. As for the vibrating part, I couldn't tell, but that's not what I bought it for. This brush generates NO heat, which is exactly what I wanted. Unlike some similar products, there are NO seams that could catch the hair.
TIPS FOR ALL IONIZING BRUSHES:
(1) if they don't need electricity (cord or batteries), they're not the real deal
(2) heating elements, just like heated blow-drying, tend to dry out your hair and make it more brittle: even oily hair can get dried out
(3) brush your hair SLOWLY to get the best result
(4) if your hair is flatter after using it, and you don't like that, bend over and brush it upside down to get more volume