I haven't read all the replies.
Greyhounds are hounds. Explains a lot. Do not expect them to act or react like a working or herding breed. Do not expect to handle them the same way either. Took me many years to learn
Like other breeds, individual greys learn at different speeds and with different methods. Huston sits, speaks, shakes, does a down and sometimes a recall. Grace: haven't even started yet. If she had been my first grey she may have been my last
I could say more, but you get the idea.
The one thing you will get from greys that I have not seen in other breeds (Dobes come close) is that for your friendship, they will share their soul with you. What more could a person ask?