The standard reply tends to be to fly through the BC just to make sure, and that you'll pick up the odd tidbit etc. I think the real benefit of going back to the beginning for an intermediate player is that you can learn how Justin structures practice sessions, and for you to learn that. You could choof through the material of the BC quite quickly. In the early stages only 15 or 20 minutes per day are required. You, as an intermediate player, are probably already playing for more than an hour a day, so you could use the extra time to build up your repertoire or work on your lead or theory or something.
Learning to practice effectively is one of the best things about this site. If you don't do the BC, make sure you do do the practice schedule lessons, because the IM is much less hand-holdy.