This paper presents measurement and analysis results for millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) performance in different real-life scenarios with moderate user equipment (UE) mobility. For the measurement campaign, the developed massive MIMO testbed operating at 28GHz called LuMaMi28GHz is employed. In this testbed, the base station has 16 transceiver chains with a fully digital beamforming architecture (with different pre-coding algorithms) and simultaneously supports multiple users with spatial multiplexing. The UEs are equipped with a beam-switchable antenna array for real-time antenna selection where the one with the highest channel magnitude, out of four pre-defined beams, is selected. We explore the potential benefit and features of mmWave massive MIMO systems with antenna selection based on both measured (and recorded) channel data and real-time system performance evaluation.