Hi cahlen,
If you take personal preference aside, too much wet climate add complexity, difficult to get warm, everything get moldy easily, no drywood easy to find on the floor if you need to make fire.
(more of a threat to immune sytem too)
On the other hand, too much barren isn't that great ether, because lack of water mean you have to carry more (heavy) and if needed it's more difficult to grow food.