Other than ecclesiastical polity, what about the SBC do you prefer over, say, Roman Catholicism or another Evangelical denomination like the PCA or LCMS? Is it more cultural, theological, or something else?
It's theological and cultural. I'm a southerner and relate to the faith better, but really the main reason is that I agree with their doctrine more. I'm one of those people (who belong to both protestantism and catholicism) that think the other side is heretical. Those people are being silly.
Out of curiosity, is your local congregation more on the Calvinist or Arminian side of the debate, or does it not take a side?