The cheap ones are just photo replicas from China mate, the materials used are completely different.
The proper ones have big soft neoprene bristles that stroke your buds to gently rotate them while the spinning wire trims them.
In the knock offs the foam bristles are really hard and are practically tyre rubber, they don't flex and stroke turn at all, completely useless.
Zedd will know what I mean as he's got it in front of him, if he posts pics later you'll get the gist of what I mean about the foam bristles.