I can read one at a glance and the other makes me fill in the blanks myself after having to count how many invisible blanks I need to fill in.

Of all the sins of IPv6, its tied between using ':' as the separator, and the god awful '::' "just skip writing the address because we made them too fucking big lol"

Wouldn't have been a problem if they hadn't given every square millimeter of the planet 100 billion addresses.