The Received Signal Strength Indicator (RSSI) is a preferred metric among researchers for localization and distance estimation. Although it is easy to use, as it is available in most of operating systems, but it is not entirely reliable when used alone. We assess the inconsistency of RSSI values in an experimental setup. We deploy multiple sniffers to investigate whether redundancy can reduce measurement errors and, if so, of how much. Among other measures, we consider the total number of packets that individual sniffers miss as well as bursts of consecutive misses. We analyze their implications on the distance estimation and on the detection of mobile targets. As a major outcome of our analysis, we estimate that a redundancy of three sniffers yields a good balance between accuracy and cost.