For what it's worth I studied the Gracie combatives program for about a year before I trained at a proper gym, I believe had I tested I could have received their blue belt or at least been very close to achieving it.
One key difference is however I would "roll" with my flatmates full force, they knew absolutely nothing whatsoever about grappling but they were all massive gym buffs and far stronger than me, eventually I got good enough that I would beat them everytime. (even got a few video'd my technique was cringeworthy looking back :redface
So when I stepped into the gym for my first class I was subtly quite confident that I would do ok. My first roll/s I got
destroyed (the lowest guy I faced was a two stripe white), that being said when I started rolling some of the guys who had been there about the same time as me, or even slightly earlier, I would dominate the roll or occasionally tap them. I put it down to awareness, in that I had a very basic idea of what could go wrong/what the opponent might attack me with and a basic understanding of posture and escapes. I put it down to awareness because after about a month or two the people I used to dominate became much better, sometimes dominating and tapping me, now with the ones that stuck with it we are really even in terms of skill.
So... Gracie University IMO achieves what it sets out to do, in that it is a good curriculum for self defense jiu jitsu, in that against an untrained opponent, even if they are bigger you can still win/not get owned. But in comparison to holding your own against a gym trained BJJ practitioner you will fail miserably.
I think Rener & Ryron are great instructors, their material is well produced and very well taught, they have done well at promoting themselves and their style of Jiu Jitsu. Between having a roll or two with some decent BJJ guys and their early Gracie Breakdowns I might not even be doing BJJ.
However outside of the whole belt thing, what I think tends to rub people the wrong way is that they never make a good distinction between their GJJ and BJJ. Personally I could care less if they awarded people blue belts in self defence, (like how they have pink belts for womens self defence) my problem is the people who get the blue belts are blue belts in a style that sounds almost indistinguishable from BJJ. And having personally gone through their blue belt qualification series, they miss alot of stuff that an actuall blue belt should not only know but would expected to be good at before recieving their blue belt.
e.g there is nothing on the turtle, half guard, knee on belly, north south, no submission escapes, no over under clinch (it assumes you always get double unders) and there is only one guard pass. Also their blue belt curriculum has 36 techniques to learn, while the 1st stripe on the blue belt has 60 techniques, seems back to front IMO.
TL.DR - GJJ is good for what it is but will only help you against untrained opponents, well at least at the 1st (presumably most common) stage
