Compared to reed switches, AMR sensors have less variation in sensitivity for enabling wider flexibility in magnet and sensor placement designs.
Also, their small size enables reduced sizes and surface installation for PCBs for reduced installation costs. In addition, AMR sensors can be handled easily because they are more resistant to vibrations and impact than reed switches, and their no-contact design allows a longer lifespan.
Because the magnetic field detection direction is the same, magnets that were used in reed switches may be able to be used without modification in AMR sensors in some cases.
However, be aware that, because the individual switches in AMR sensors have their own circuits, they require a power supply for operation, and consequently, AMR sensors may have different numbers of wires and current consumptions.