Reliable server pooling (RSerPool) is a protocol framework for server pool management and session failover, currently under standardization by the IETF RSerPool WG. While the basic ideas of RSerPool are not new, their combination into one architecture is. Some research into the performance of RSerPool for certain specific applications has been made, but a detailed, application-independent sensitivity analysis of the system parameters is still missing. The goal of this paper is to systematically investigate RSerPool's load distribution behaviour on changes of workload and system parameters, to determine basic guidelines on designing efficient RSerPool systems. In this paper, we focus particularly on scenarios of server pools consisting of servers with unequal capacities.