The Selection Guide (pasted below) of ACS712 data sheet says that the sensitivity value of 100mV/1A is a typical value, and it agrees what the data sheet has announced in the summary -- sensitivity is 66mV - 185mV/A (66+185/2 = 125). The ACS758 does not use the word typical; it clearly says that the sensor is factory calibrated and the sensitivity is this much for this much current in the hot circuit.