Snowdown chests

I'm currently thinking of buying one of the snowdown chests as i think they are very cool, but are they worth it? The legacy chest includes a legacy skin and im not sure if i will even get a skin that i like. The snowdown chest includes a skin with a theme that changes each day, i think of buying this when the theme is snow as the snow-themed skins are mostly legacy or snowdown skins.

Also, if i own a chest before the snowdown update when i unlock the chest does it give me a candy?