A series is much better than IXUS series in sensitivity and zoom, but the disadvantage of A series is that it uses AA battery, while IXUS series uses Canon's special lithium battery, which has memory function. IXUS series is fashionable in appearance, small in size and convenient to carry, while A series is relatively large, and its appearance is far less than IXUS series. The performance depends on your own needs to decide which series to buy!