Many test selection criteria are considered for the derivation of functional tests for reactive systems and protocols modeled using formal techniques such as Extended Finite State Machines (EFSMs). In this paper, we consider three known EFSM specifications and analytically compare the effectiveness of many EFSM test suites. The assessment is conducted using EFSM mutants of these specifications, namely, EFSM mutants with single and double transfer faults. Test selection is based on deriving single transfer fault, double transfer faults, All-
Transitions, Transition Tour, All-Predicates, and All-Uses of context variables test suites from the given EFSM specifications and their corresponding flow-graph representations. An order between these test suites (in terms of fault coverage) is establishedfor each considered type of faults. Data flow scores of the best performing test suites are also determined. Further, an initial assessment of test suites randomly generated from the considered EFSM specifications is reported.