It all depends on where you are, what you monitor, and the type of signals. I dedicate one scanner to each TRS in my area. Another for conventional. Another for CHP (low band VHF). Each of my scanners have different antennas feeding them, because CHP needs VHF low and all the TRSs I monitor are in the 800 MHz band. Some people enjoy listening to marine, aviation, amateur or other such bands. If your area does not have much LE/fire traffic, then you can leave a scanner there and listen to chatty stuff elsewhere. There really is a LOT to listen to.