Response time seems to be the biggest weakness on the ACS, at least on the high current versions. They have 1mhz versions with sub 1us propagation but they never release them in the high current versions for some reason. The INA240 I have been using recently is faster but they are limited to 80V and shunt resistor heat is an issue, you gain a few watts worth of heat at 100A+ and accuracy theoretically suffers as resistance changes. An isolated current shunt amplifier I tried is faster than high current ACS but still had the down sides of resistive sense. I'm not sure how fast is fast enough for motor control, considering a worst case scenario of a motor with 200,000 ERPM you still have around 300us per electrical cycle?