A number of steam turbine prime-mover models for extended system dynamics simulation has recently evolved and been documented from planning type of studies. Significant effort has been expended in the development resulting in some general awareness of this applicability. However, the effective model structure as affected by limited data, and individual dynamic response characteristics of these state-of-the-art models remain to be considered. It was not known how these models individually respond dynamically in terms of closed-loop response time and nonlinear effects such as dead-bands and limits. It was also not known how well these models can be used in a dispatcher training simulation. This paper presents computed results of individual unit dynamic responses of two such models out to several minutes. Computations simulating load following and breaker opening are included. The responses show nonlinear effects due to dead-bands in series with major control paths. The closed-loop response times are found to be not directly related to any single time parameter of the model. Effects and limitations of integration time steps and integration methods are illustrated. The results of the computational study show that the models can be adapted for dispatcher training simulation, and time steps can be as long as two seconds with appropriate choice of integration algorithm. Computational interface consideration for these models in other power system studies is also included in this paper.