Its been noted that the client is 70gb for NA/EU but only ~50gb for RU. It should be fair to assume that 20gb differential is caused by voices for the 3 extra languages (~6.6gb/language); especially when we consider RU will have more content released. It would be nice if we could select the voice pack we want to use and delete the unused ones since 20gb is 40% extra disc space or 54% for people who download the Korean voice packs on top of that.
Origonal source of download size: