First, I didn't get the design advertized. Still don't know if that's Amazon's or Icon's fault... So I got the skull design, which I didn't enjoy much. But paying for shipping and waiting wasn't an option.
The noise difference is not as noticeable as I was hoping for. I don't know if the difference I had heard people talk about is with these pads or with others. I'm guessing it's with others!
You don't so much hear less pounding as a different sound. It's more of a bass sound, lower pitched. Muffled a little. A LITTLE.
The smell was horrible when I got the pads out of the box. A horrid rubber smell.
It wasn't easy positioning the pads perfectly and if you miss the first time, the adhesive doesn't work well anymore a second or third time, and they don't come with a set of replacement adhesive.
Since I had trouble placing one pad, it wasn't sticking well to the drum pad and wasn't responding well (it was lifting up all around except in the very middle, so when I would hit the pad on the sides it wouldn't always register right away... plus it looked awful!).
I was very disappointed that the pads didn't come with reusable adhesive and was worried that it would ruin my drum. There was no information on the packaging about anything and I couldn't be assured that it wouldn't. For example, it didn't mention the fact that you would better put the pads right the first time, because they wouldn't stick anymore if you repositioned them!
After just a couple weeks, the foam became cracked.
Since they didn't look very good, since I had 2 which were lifting off a lot, since the other 2 looked like they were starting to lift off too and mostly, since I felt like the drum wasn't as responsive with the silencing pads as without and the sound wasn't even that muffled, I removed them within a month!
The good news is, I can now say the adhesive didn't ruin the drum pads. I only have a little adhesive residue on the middle of one or 2 pads.
I continue using the sticks though, even with the skull design I'm not a fan of, because they are painted, unlike the original Rock Band drum sticks, and I hate the feeling of raw wood.
So final line : don't bother paying for those silencing pads. If the sound of your punding on the drums really bothers you, pay more and try better quality silencers.