They are average but I wouldn't call that good. They also have, IME, nasty personalities~every single one I've had over the years have been unpleasant birds~and I don't even love and pet on my birds, so I don't require much docility, but these birds are nasty to other hens and to humans. They are a heavy bird and eat quite a bit but it doesn't pay off in the level of lay.
One good point of Wyandottes...they are excellent to train a pup on to keep him away from chickens. I used one for this purpose on a high prey dog/herd dog breed mix and he hasn't looked at a chicken sideways ever since. She pecked him pretty hard on the nose and went crazy in his face and that was all it took!