If you are after a good working deerhound, I would definately go for one from a noted working line, the show ones have been getting bigger and bigger for the last decade, with the ban the Deerhound Club has curtailed all organised coursing events, and not a lot of owners work their animals on rabbits. A lot of show animals also have their hunting instincts practically bred out of them.
Ive seen proper working deerhounds take 20 plus rabbits in one night, kill 14 blue hares in one day, take brown hare, and fox, well, ALL proper deerhounds hate fox, also, witnessed a deerhound bitch winning it