Simulation-Based Training is a force multiplier that contributes to the success of our Warfighters. Software and hardware tools available today present critical visual and auditory cues to provide opportunities to integrate traditional training methods, gaming techniques, and emerging technologies. Two software applications at the forefront of the industry are Bohemia Interactive's Virtual Battlespace 2 (VBS2) and Crytek's CryENGINE®3. The present research investigated the usability of the VBS2 Editor Interface and CryENGINE®3 Sandbox; thus, the experiment focuses on the experience of a scenario developer as the user, rather than a trainee. Questions related to sustainment costs were derived from human performance assessments by focusing on scenario development (i.e., object placement and scene alteration). Following introductory training, 30 participants completed a set of pre-assigned scenario development tasks within each application. Accuracy scores and response time were tracked. Participants were characterized by five sub-groups (i.e., full sample population; males, females, technical and non-technical only), who completed several assessments. One of the assessments included a usability questionnaire that addressed general fidelity, operation within the graphical user interfaces, and additional inquiries from subject-matter experts. Subjective information concerning each user's experience was also captured in order to identify favorable functions and describe features considered difficult to use. Results from paired t-tests revealed significant differences in Task 1 response time between the platforms for the full sample population. In all cases, users completed tasks faster using CryENGINE®3. Independent-sample t-tests showed statistically significant differences for VBS2 overall accuracy scores as well as VBS2 Task 1 accuracy scores whereby males scored higher than females. However, the practical significance of these results is questionable as the Operations and Maintenance savings for developing scenarios using CryENGINE®3 is estimated to be at most $4000 per site.