I really love the bonus sections of B&G - either the abs section (15 minutes) or the abs section plus the three sets after it of sit-n-stands, step ups and glute lifts on the ball. All told, that's 25 minutes of intense LB work with its biggest focus on abs. I love those glute lifts laying on the ball - those get lower back and glutes and help address those little soft pads on the back of the waist that are my nemesis. I would have bought this workout for those sections alone. But to answer the original question, I've only done B&G all the way through a handful of times.
"You can do anything for one minute. And at this point it's not even a minute!"