Usability and user satisfaction are critical for Electronic Health Records. This study evaluates DIPS Arena, a hospital-based EHR, and compares the System Usability Scale (SUS) and the National Usability-focused HIS-Scale (NuHISS) in predicting satisfaction. A cross-sectional survey of 127 users across three hospitals collected the SUS, the NuHISS, and satisfaction data. The SUS was a stronger predictor of satisfaction explaining 45% of variance. The SUS scores were higher and more consistent, while the NuHISS provided task-specific insights. The SUS effectively predicts satisfaction, but a combined usability approach is recommended. Interoperability challenges in DIPS Arena impact usability and Valkyrie’s Virtual Health Record could enhance data integration. Future research should refine usability frameworks with subjective and objective measures.