The transition from 4G to 5G networks necessitates a rigorous evaluation of 5G's impact on mobile network performance and user experience. This study investigates the claims of enhanced connectivity and higher speeds by conducting speed tests and surveys on MTN and Airtel 5G networks in Yenagoa, Bayelsa State, Nigeria. Utilizing a mixed-method approach, data on upload/download speeds, latency, and network strength were collected over 37 hours from April 29 to May 1, 2024, complemented by questionnaires from 88 respondents. Results indicate significant variability, with MTN peaking at 41.8 Mbps (upload), 72 Mbps (download), and 491 ms (latency), while Airtel reached 37.4 Mbps (upload), 30 Mbps (download), and 220 ms (latency). Pearson correlation analysis revealed weak relationships among performance metrics, suggesting independent optimization potential. Despite some improvements, 5G performance fell short of expectations, highlighting infrastructure and stability challenges. Recommendations include network upgrades and better traffic management to enhance user satisfaction and meet 5G's transformative potential.