This is just my opinion, but also based on my experience. A well rounded group offers a Beginner's meeting, a Big Book Study and a 12X12 Step Study meeting. Closed Discussion meetings can fill the gaps. One of the questions I have is how many meetings does your group have? Are you saying that the only meeting your group offers is a 12X12 meeting? I will say this, if I had to choose between a Big Book Study and a Step Study I would opt for the Big Book Study first, and add a Step Study on a separate day when participation/ attendance would support it. The reason is simple, I do my work out of the Big Book. While I will refer to the 12X12, I use it along with NEVER instead of the Big Book. This may sound like AA heresy, but I liken the 12X12 to any other book I might have on the side whether it be Sermon On The Mount or something by Merton. They can all be useful, but my foundation must be the Big Book. It's the only place I have been able to find a solution that works for me.