i have a first cross that i bred seven years ago, the dam a racing bred greyhound from ireland, the sire was a blue welsh hill collie, very strong boned dog not like any other collie ive seen since. Pups had a bit too much bone which affected the speed, and agility of the ones i saw run. the one i kept was a dog, made 26''tts and more like a 3/4 bred to look at but still could not turn quick enough. personally i would prefer a hal cross put back to a grew, the touch of whippet would create sharper dogs that can turn much easily.