broodiness is a good trait to have, in a backyard flock. I personally keep a few silkies around, just for that trait of hatching eggs for me. Usually though, it seems when I have something broody. I don't have any eggs. If your at all wanting to expand your flock, or make is sustainable, and you have either average incubators or incubator skills... then a broody chicken is the way to go. Sometimes though, I find myself wondering what is more sustainable and ecconmical, feeding a broody to be hen all year, or running electricity in the 'bator for 21 days at a time....
Combs can be very important, somewhat for the backyard flock as well. In colder enviroments, very large single combs, and average sized singles can get frost bit. Another thing to worry about is the fluff on silkies, or Polish-- that tends to be high maintance in terms of keeping it dry and clean, or trimmed. Just as important to me, is the feathering of the legs... In a chicken producing system where the birds will be let free range, or couped on the ground-- i discourage feather legs-- just due to keeping them clean and tidy looking. Maybe it's just a personal objective, but I feel that feather legged birds are not as good of free rangers due to this.