Balmer lacks intensity and Smith is too slow. I still expect that Balmer will provide decent depth at the power line positions, but Smith definitely needs to play exclusively at free safety.
Not to belabor the point, but back on draft day I was hoping for Curtis Lofton at #29. The reasons were obvious: he filled a need at SS-ILB, he had the big body to take on blockers, and he seemed like a perfect complement to Willis. It turns out that Lofton had a solid rookie year for the Falcons and is poised to be a solid starter for years to come. But I understand why Scot chose Balmer. We desperately needed talent on the d-line and Balmer was the most talented lineman available. It was a risky pick, and so far it hasn't panned out.
Right now, our defense has a deep stable of average players. We need some stars, some impact players, especially along the D-line. Unlike an offense, a defense wins with pure talent. This is especially true along the line of scrimmage (the DLs and the CBs) where the matchups are head-on, mano-a-mano. We need to win those matchups, and the only way to do that is to get defenders who are better than the offensive players they are matched up against.