Pros: good broody, good mother, delicious meat, lay pretty well, large clutch
Cons: Produce sterile offspring if bred with other ducks and I guess claws
Muscovy are great birds to raise. Quiet, good foragers, excellent at bug control, many colors. I raise mine for meat. Their meat is similar to beef, not at all fatty.
Typically (there are differences in every bird of every breed) they are great broodies and great mothers and will sit on a huge number of eggs. In most areas, they are seasonal layers. Right now, I have a hen sitting on 22 eggs (it is her first time going broody) and it is the end of November. I have had a hen hatch out 11 of 14 eggs before and all of the hatchlings survived.
They are a great breed if you don't want the loud quacks of other breeds. Don't get me wrong, they still make noise. When my girls get to whistling you can hear it you just wouldn't think it was a duck.
The males get BIG, some lines get huge.
All muscovy have claws, the breed is a perching duck so they need them to climb and cling to branches.
In my experience, people that say that they are mean birds have raised them as pets and when the hormones start, the bird changes and the cute little duckling turns into a hormone machine. Again, I don't coddle mine. They are treated well but they have a purpose. I don't handle mine but they still will come up to me for food and eat out of my hand.
The hens are protective of their babies, but that is only natural.