The paint and dirt thing that everybody else says. Sound reduction is barely noticable. I did not however had a problem with the screws being different size like everybody else says. The screws that came with my Rocket Cock are the same size as the ones on the M98.
Weaknesses:
It's plastic, I'm afraid that the ring will break off. It was abused a bit and still held so I hope it keeps on holding.
Conclusion:
It'd be better if it wasn't plastic. If you're handy enough with tools, make one yourself.
