One of my students just brought in a nice looking Invader V3 practice pad so I had a chance to test it. The pad is made by OffWorld Percussion. The build quality is great. The pad has a solid plastic rim and you can fit it perfectly on a 14" snare drum. The playing surface is made of yellow gum rubber, which has a similar feel to well known HQ Real Feel pads (discontinued). While stick response feels good, I found the rim to sound a bit too loud. It's possible to practice rim shots on it, but it won't sound proportional to the real drum head (you will hear a lot of rim and almost no drumhead sound).
Leonid Sokolovsky