My only issue with these is the how light and hollow they are. I think they would give off a more quality feel if they were heavier somehow. Also, I realize the color is why these don't have your standard rubber coating, but I feel like there should be a rubbery glow-in-the-dark material available that could meet this challenge. I ended up putting these on a sampler that I wanted to feel more like a toy. However, I have purchased some of your knobs with the more standard pro-type feel, and overall I am very much a fan of Chromacaps.