I replaced the standard CE armor (cheap-feeling plastic) in my leathers on the knee/shin and the elbows/arms. When I'd previously crashed in the standard CE plastic armor, the joules of energy burned through to my skin. This quattrotempi research published by the mfr says it absorbs much more energy in a crash, which I'm hoping keeps me more intact. However, until I test that (hopefully never), I can say that it is FAR FAR more comfortable than the standard hard plastic CE that comes in gear. It warms up with body heat and conforms to your curves, so it just feels natural. Plus, it is actually the exact same size as the standard stuff, so it fits right into the same pockets. And, it has velcro on it to help keep it in place inside the pocket. Soft comfort that protects better - you can't beat that.