I'm at the top of the blue's now-a-days. The rubber guard is great for competition, both jiu-jitsu and I've seen some people have good success with it in MMA.
I don't pursue it myself, because Bravo's method seems to be so...off the beaten track. I would need to totally revamp my current game to pick up the rubber guard and twister. I'm flexible, but Bravo is ridiculous flexible. I try to stick to the basics/fundamentals so that when I teach I can relate to more people. Imagine trying to teach a room of inflexible people to pull their foot up to their chin...just not going to happen.
I think a good butterfly guard and side control will get the average person a lot further in the long run. Just my .02
What do you think??
JonV