Quite honestly, the A320 series is a flying brick house and easy to get down, even the A321. But then, that is coming from the 738 short field performance.
Apart from that, the usual 3 times table is conservative and keeps you on the safe side in my experience. Of course the usual adjustments for strong tailwinds apply. And the donut can help of course as well in energy management. Just download an up to date wind profile before you start your descent.