The Tech Report brings up the multi-GPU micro-stuttering issue as they discovered a video that captures the effects of this problem quite nicely:
Very educational. I take several lessons from this video. One, it validates my argument that the high-latency frames in a jitter pattern can be the gating factor for the perceived illusion of motion. Although the multi-GPU setup produces a Fraps readout of 60 FPS, it looks no smoother than the single-GPU setup at 30 FPS, and multi-GPU at 30 FPS doesn't look as smooth as the single GPU at the same rate. This case may be an extreme one, but the effect of those high-latency frames is clear.