You get what you expect.
Walker writes solid military sci-fi. This series has got everything you want; fighting aliens, cool technology, one ship fighting against impossible odds. However, he wants to tell a larger space opera, which means LOTS of characters. You need bridge staff, engineers, Marines, pilots... as a result, you don't get a real good development on most of them. So you might understand four or five characters, but the rest are just names, and if you're lucky, a basic personality. The plot is decent, the enemies are enjoyable and have faces, but a lot of stuff happens in ten short books. Enjoy the ride.