I brought got a non ped whippet out of a racing kennels for my son and it has turned out to be a very useful little bitch. It is 21-22", 28-30lb, 3years old now and I am quite keen to line this bitch soley for her speed, drive and nimbleness. She catches as many rabbits as I am willing to carry and she is a good catch dog but lacks finish. Obedience is great, she is lamps of the slip, retrieves, jumps and is very steady.
I would say there are many reasons for using racing stock, but as will all pups you pay your money you take your chance and as aways it is what you put into them that turns