One big difference is that they're two completely different hybrids; 'Aphrodite' is agnata x moctezumae, not moctezumae x gigantea. Coloration is probably going to be different (I can't imagine the gigantea hybrid getting much beyond a light red tinge, while the cultivar gets really purple), flowers will look different, etc. Leaf shape in a general manner is in fact really the only similarity.