Our next door neighbors have two greyhounds. At first they just had the one and she would howl while they were gone. They are used to being in a kennels with other dogs. After they got the second one we haven't heard a howl out of her. They are nice gentle dogs but as watch dogs they are worthless. I guess it depends on what you want out of the dog. They are both rescued dogs.
We got a rescued Corgi/terrier and he is a wonderful dog. Gentle, great with the grandkids. He can scare people half to death at the door with his nasty viscious act, and it is only an act. Only twice did he mean it and it was a darn good thing I had a hold of him. He has no bad habits, other than hogging the bed at night.
MillieBTW, did you know that greyhounds cannot sit down? They have a real little head and big hips that just do not sit. Hard to keep a collar on them too.