Drumshhh Just Works!
Placed these pads on my Rockband Drum Kit (EL Model--with Nickel Mod), and they work beautifully. Significant silencing of the drum hits. Look cool also. Does not seemingly result in any missed beats either (probably du to my Nickel mod).

Easy fix to an obvious problem
Anyone who's played Rock Band knows how annoying it can be to play with the drummer. The drums are just too loud, and nobody likes the sound of a wooden stick hitting plastic over and over again. If it actually sounded like a drum it might now be so bad. The fact is, you have to crank up the volume so you can hear the songs over the beating of the plastic drumset.

This solves that problem. Very easy to apply, it doesn't effect the playability and it dampens the noise.

My Rock Band members are much happier, and so am I!

GET THIS THING!!!
Bottom line, if you play rock band, you will need this. This thing will reduce the drum set noise. Of course it won't make it silent, but it will reduce the noise a lot and it is a good protector for the drum set surface.

Good - but there's a better option
Pros:
These felt drum pads are very good at dampening the noise from your loud Rock Band drum kit.

Cons:
They also reduce the re-bound from the drums, which makes it harder to play Rock Band.

Solution:
I bought these and used them for a couple months, but then I switched over to the rubber drum pads produced by the makers of Rock Band themselves. They eliminate almost as much noise as these do, but they don't reduce the tactile feedback you get from hitting the drums (the rebound or bounce-back). They let you reduce the noise from the drums without sacrificing your play experience:
Rock Band Drum Silencers

Other notes:
For both of them installation and removal is easy - they're just like thick stickers you put on your drums.

Make sure they are right for your drum kit model...
I bought the full size Drumshhh pads for two reasons - to help decrease the noise of my Rock Band drum kit and to protect the pads on the kit. While these pads did decrease the noise quite a bit, I found some major drawbacks to their usage.

I have an EL set of drums, which are known to be less sensitive than the other Rock Band drum models. These pads, unfortunately, decrease the sensitivity even further, causing for more dropped notes and having to hit the pads harder (a potentially damaging situation).

I recently attempted to remove the Drumshhh pads from my set, and they made a complete mess of my drum kit. I now have felt and adhesive all over my drum pads. The instructions that come with the Drumshhh pads do indeed say that they can be removed (and I tried per their instructions), but fully removed? No such luck. I'm now left trying to figure out how to remove the remaining felt and adhesive without doing damage to my drum kit and voiding the warranty.