no it isnt!!! i ve driven it.the acceleration in first 2 gears is around 85% that of the 1000cc alto.but the drive of japanese alto is brilliant... the electric power steering, the brakes, power windows etc give u feeling of a nice pricey car.not like that of the local alto which starts to break apart in the 2nd week of delivery.
plus the suspension of jdm alto is also much better , keeps the car stable n more comfy.i wud certainly like to have the 660cc jdm alto over the local one.as far as performance, i dont think the 1000cc alto is just 1.2 seconds slower then the Nissan GTR on nurburgring so i think its ok for it to be slow.