[GlennGraham]

Thanks,

I'm going to lock the encoder shafts and try to get a good characterization of the latency between reads. My first thought is that I will probably have to read left, read right, read left and then compare the average of left with the value of right if my goal is to match motor speeds. Also, dropping the speed when it gets close to the destination value might reduce the overrun.

Sweeping the sensor with a servo sounds like a fun next step. Set up an array, record the sensor values, then identify the position and value of the smallest (closest) reading to get the heading.