Thank you to Kevin Murphy (ZL1UJG) (aka Tech-ni-shn) for writing in and submitting some RTL-SDR and Airspy sensitivity measurements that he has recently done over on his YouT ube channel. In his tests, Kevin measures an RTL-SDR Blog V4, RTL-SDR Blog V3 + SpyVerter, Airspy HF+ Discovery, and Airspy Mini using a signal generator, attenuators, and SDR#.

His results show that the RTL-SDRs and Airspy devices have very similar minimum discernible signal (MDS) levels, all measured around ~-133 dBm. Kevin has provided a PDF summary of his results, and the video below.