I got the black ones for the xbox 360 controller that had completely worn out the previous ones. I had to put something inside for them to fit, but okay, the controller was refreshed. On xbox one, they fit perfectly over the original grip. I believe they help with better handling.

It's okay. It's not as smooth as I thought, so it's suitable for someone who doesn't mind that. I suppose you get what you pay for. Time will tell.