We have investigated the performance of various optical packet switched network (OPSN) architectures comprising optical bufferless nodes and fully connected mesh topologies, under uniform traffic distribution, i.e., all nodes generate the same traffic. We demonstrate that increasing the number of nodes in OSPNs does not necessarily increase performance, or even capacity. By establishing an efficiency parameter based on average number of hops and effective network capacity, decision tables and graphs can be generated and utilized in network planning. Moreover, regular and quasi- regular optimized topologies lead to lower latency, higher throughput, and lightpaths with significantly better traffic distribution. The optical nodes have simple configuration and are totally compatible with WDM networks.