Motivated by issues in size-aware routing, we study a multiserver model with a single FCFS queue and two types of customers. Our interest lies in determining the probability that an arriving customer waits as a function of the number of servers. We find that matrix analytic techniques yield an efficient, scalable algorithm to calculate this value. We leverage the developed algorithm to gain insight into system behavior, in particular suggesting that the convergence of this probability (with respect to the number of servers) is fast. This is work in progress.