The ES 330 has more sustain and and much more beef on the bottom end and the high side its just not as thin as the Casino.
Many people compare the two Gibson and Epiphone and although there are those who believe they sound the same in my experience believe me they very much don't. I have a Casino Inspired natural its about 4 months old and a Gibson ES 330 VOS and in the past a Elitist as well.