Dried seaweed is easier than raw because it may be difficult to obtain raw seaweed, and the shelf life is very short. Raw seaweed is usually just frozen seaweed that has been thawed, and won't have that fresh crispy feel to it. It will, however, be pretty decent, with lots of flavor left. Raw seaweed works excellently for food that needs wrapping, like cured or baked fish and meat. The seaweed retains moisture and flavor, while adding a subtle touch of umami. Dried and milled seaweed is in many ways easier to use because you can often times simply add it directly, like soups and sauces. You could also just use it as seasoning.
It is important to note that while seaweed is a great source of iodene, the concentration could be so high as to pose a health risk for vulnerable groups. Make sure you read and understand the product label, and follow the instructions if you are unsure.
