I’m using those chips in my LED/battery analyzer (Any interest in a LED/Battery analyzer device?). They also make some higher current versions (ACS758 series) that have 1/10 the burden resistance. They are VERY nice chips.
A neat feature of the chips is that the output signal is totally isolated from the input current.
A not so neat feature is that the 0 input curent reading is not exactly centered on the input voltage and seems to be somewhat temperature dependent. The REL button on your DMM gets around that neatly. On my analyzer, the firmware auto-zeros the reading each time you reset the board.