Pros: Adorable as all get out, good broodies, goes on and on
Cons: Can't evade predators well
We had some silkies and they were the cutest things. As chicks they were the first to spot anything edible making them great foragers. They were bright and inquisitive. I know people can spend time with them and make them very good pets.
Also, I bought some after hatching a mixed group of chicks. The purchased silkies were so kind and mothering to the younger mixed breed chicks - both male and female were mothering. They really looked after the younger birds.
I've heard (and agree with) having a flock of silkies is like having a "flock of kittens". Their feathers are more like long fur. Their bright blue earlobes are so pretty.
I know they go broody which some people like but it could be a con.
The eggs are smaller but I didn't mind that. The silkies weren't the main birds in my flock, they were for fun.
My nieces loved them, they want me to get more but they cannot fly as well as other chickens due to the fluffy feathers they have and therefore cannot escape predators as well as other breeds. We free range our chickens with no fencing and the silkies didn't last long. So as much as I'd love to have them again, I won't for their sake. If I ever have a large safe chicken yard that is fenced with roof netting I'll try them again.
My uncle's sister had a white one named Pearl that she had for years and hers are free range birds. But she has other farm animals that probably help keep predators at bay. I've heard livestock can really help keep your birds safe.