A avalanche beacon is always ‘on’. A PLB only when activated. Pushing the button on a PLB can be an issue when buried under 10 feet of snow…

The two devices are for different uses. Not much point having a PLB, even if its activated if you are buried in a avalanche. Your most likely dead by the time rescue shows up. A PLB sends a message to search and rescue by satellite. It takes time for the too arrive. A avalanche beacon is only useful when you travel with others, also equipped with beacons, shovels and probes. A beacon is short range device and only useful if the rescuer is close by. Time is essential for avalanche victims.

A PLB is nice for other emergency’s in the mountains, when you can wait for rescue.

Best advice is not to travel alone, wear avalanche beacons, snow shovel, probe and a PLB.

Oh and what do you mean with mountaineering exactly?