Be interesting to hear other people's opinion on this too.
My brother in law's dog, gc beddy x whip/grey, 20 1/2" was no slouch over about 50 yards, but was sometimes made to look a little lacking speedwise, on the lamp. And if a hare got up, he had no chance, only seen him catch one, and that was lucky, and when he missed, would then be head down and gone for the next 15-20 mins. Daytime, he was a cracking dog, and caught well, and would work tirelessly all morning.
I know not a 1st x beddy/whippet, but roughly the same size. I think if a 1st x turns out quite small, say less t