Having owned a pure whippet and whippet bred lurchers I don't think I'll own another unless it was a whippet x grey. They aren't big enough or fast enough for the ground local to me.
had a racing bred (none ped) whippet bitch 20in 20lb great little rabbit dog, some of the male dogs at the track went up to 36-37lb very fiery things you could see bit of staff in them, I liked them types of whippets . But I know what you mean with a whippet x grey , just that bit more bigger /tougher type , if you got one about 23in 40lb that be bang on for rabbits, plenty fast/agile enough , feck me my