Yes, ducks lay larger eggs for longer amounts of time than chickens do. They're also great for baking.
But, ducks can be quite messy. Their poop makes a mess, they make a mess with food and water, and imo they're a bit noisier than chickens. Though that depends on the breed and individual duck.
Ducks do need some more water since they have to wet their food, clean their nostrils all the way out, and they love to play in it and it helps to cool them down. All you really need is a kiddy pool, though you'll need to dump it out about every day (depending on how many ducks you have).
I absolutely love ducks. It's so fun to watch they play in the water, waddle around, and the way they get food is just so cute. They are great for eggs too, especially Khaki Campbells and Welsh Harlequins.
You could get both ducks and chickens. Though I wouldn't get more than one drake if any at all with hens. They have a penis while roosters don't, which can hurt the hens if the drake were to try to mate them.
And having ducks means having a lot of moisture in the coop, which is one reason why I would not keep them in the same coop together with chickens. Also, since ducks nest on the ground they would get pooped on if the chickens roosting bars were above them.
Though the could still share the same run. Or you could have two separate coops, which would work best if they don't get free ranging time.