I'm not sure about the greyhound but, I have the Irish and one is
very hyper the other one is not that bad. One would lay around alot
more than the other one.And one paces steadily and wouldn't sit still
for five minutes.

However give them a chance to run and then they both are great dogs.
If no chance to run I don't think I would have a house left to come home
to. With the chance to run I don't think I could find a better dog nowhere.