If you are contemplating buying a portable radio for receive only purposes, I'd like to offer the following suggestion.
Before plunking down $ on a radio, you may wish to find out whether you can even get the radio programmed to receive the MetroSafe system. For necessary security purposes, there are several layers of security settings, requiring special "keys" in order to program radios. These "keys" are closely held by the MetroSafe radio folks (which is fine with me as a system user).
My technical knowledge level isn't high enough to know whether the security keys are required for "just listening" versus "full use". I do know, however, that programming a system/radio like MetroSafe is a lot more complex than the old analog conventional radios.