This paper reports our experimental results with the Passive Cavity Gyro (PCG). The angular random walks in our long- and short-term drift runs are within a factor of 3 of the setup performance limit. Optical misalignment tests indicate fairly low sensitivities of the bias and random walk to component misalignments. The PCG concept allows for the development of very high performance gyros. Also, recent results in fabrication of low-loss waveguides make PCG an attractive candidate for developing small, low-cost gyros.