The rocket's main usefulness, according to this link, http://www.brighthub.com/science/space/articles/3348.aspx is that they can more safely reenter earth's atmosphere. In order for the shuttle to reenter, it must be turned at an awkward angle, and it still encounters temps much higher than the rocket.
This doesn't mean that the shuttle doesn't have its perks. While they are both sent into space much the same way, the shuttle is more once its there, and is more easily landed once its back in earth's atmosphere, as it can be landed at an airport, and the rocket is most often landed in the middle of an ocean.
The shuttle is what NASA has been using for quite some while, but we began with rockets. It looks like the rocket is going to have a resurrection, from the link I put up there.