Good and fair question. I don't know that there's a Cardinals message board as well run as this one -- at least not one that concentrates 100% on the Cardinals, as you do the Reds.
I know that I found this board after one of your members came on a STL-based message board (tippingpitchers.com) and started a bit of a flame war. He's subsequently become an off and on-again regular poster, and the flaming has greatly subsided. He's the one who made me search out this site, as he referenced it multiple times.
Personally, I enjoy seeing what other fans are saying -- and specifically saying about my team. And I enjoy discussing their opinions when I think they're off or just plain uneducated.