ODA X4-2: Anyone Use Copper for the Interconnect?

I'm wondering if anyone has setup their X4-2 cluster using the RJ45 for the interconnect. If so, do you have any latency issues?  Our ODA X4-2 clusters were setup with fiber for the interconnect however, we don't have any 10GB copper switches so our public interface is negotiating at 1Gb. With the recent enhancement to oakcli in 12.1.2 allowing to change the public interface I'm considering changing it. This is, assuming the "oakcli configure network -publicNet" switch handles the interconnect swap in the process.