it was instant as far as our own stuff in my area was concerned, it gives a coolness to the offspring, take a f1 for example straight away you kill the raw aggressive almost reckless pace from the greyhound, and adds the calmness of the saluki giving a dog straight away that is more difficult for a hare to deal with. a flight animal can deal with a dog coming at it fast trying to out pace it, a dog that steady's when it gets there and watches and reacts to the hares movement is a different proposition altogether, when I watched dogs running, I watched it all. some times talking to a mate after