This dataset presents the evaluation results of the Literature Gap Analyzer, a RAG-based prototype for automated research gap identification, developed using Design Science Research Methodology (DSRM). The evaluation was conducted through two complementary approaches: 30 automated test sessions measuring system performance across four analysis domains, and a user study with 228 respondents using the System Usability Scale (SUS) and a custom Perceived Usefulness instrument. The dataset includes anonymized survey responses, descriptive statistics, system test logs, and the full survey instrument. Results cover SUS scores, perceived usefulness ratings, manual time baselines, and API performance metrics, and are intended to support reproducibility and further research on LLM-assisted literature review tools.