[alexeckermann]

This is entirely dependant on the beacon antenna design and its configuration. I have tested various beacons and have found that beacons using ceramic chip antennas do give these wild and unpredictable ranging values where as a trace antenna, especially the ones provided by TI, are exceptionally good once configured with correct TX power settings.

Using Apple's devices as iBeacons are very accurate. I usually have an margin of error in the region of +/- 10cm at its worst.

But the point of beacons is that they represent a physical thing. "A thing is here. Have its identifier" rather than using GPS or a-GPS to resolve a 2D coordinate that then needs geospatial querying to find an object "closest" to that reported position. No matter how good 2D coordinates are if the thing doesn't stay in one spot or if the accuracy is not great (indoors) then its just a guessing game.