Sun is, with out a doubt in my mind, underated. Both Ninetales and Victrebell get plus fifteen boosts while Victini gets to spam sun boosted and banded V-Creates off a 105 stat instead of a 100 stat. That said the problems I have with sun are still consistent with the problems I had with it in fifth gen (when I was primarily a sun user) is that to a degree you lack the variety that rain and sand have for extremely abusive power. For example while sand doubles the spdef of all rock types and doesn't hurt any Pokemon of a decent three types and rain dampens the fire weakness of support mons that are weak to it as well as providing any dry skin mons with dry skin support, sun increases the fire weakness of the chlorophyll abuser and you'll probably end up with multiple fire types (which isn't that best defensively).
That said, there is an insane amount of power in sun and the playstyle is incredibly fun and I would like to spend this sentence urging more people to use it while spamming banded vcreate victini in the sun. Trust me, you'll enjoy it.
