Pros: Great foragers; Large birds; Feather color conducive for free range.
Cons: Noisy; flighty; small eggs/not so great production.
I purchased my Welsummers at 8 weeks old, however they were tiny and sick with coccidia. They were improperly kept until I purchased them and had no enrichment what-so-ever. Despite this they were able to integrate with my existing flocks wonderfully and enjoy free-ranging and the often handed out treats. They are however non-trusting and flighty. I have gained much progress with them, having gone from a simple movement like scratching your nose and them flying up and freaking out, to hand feeding them.
Their eggs are beautiful! Their plumage is luxurious and vibrant. They are great at foraging around the farm and finding things to eat. They are however very vocal and when the lay an egg or are about to, everyone in the neighborhood knows it!
I would definitely purchase them again from chicks as I'm sure the behaviour of my flock had a lot to do with their chick-hood neglect. 
Thanks.