Sean Springer, an instructor at RSA, recently sent the following articles on Jiu-Jitsu styles and effectiveness. I believe they are important reads for the serious, experienced and novice practitioner.
Ronn Shiraki Academy
The Relson Gracie Ronn Shiraki Academy (RSA) is a small, low-key but highly advanced Brazilian Jiu-Jitsu school located in the heart of Honolulu, Hawaii on the island of Oahu. We are dedicated instructors who strive to provide a pure "art" and soul martial arts environment with a focus on traditional methods of training.