Outward Frontier grew steadily on me as I read through it. It consists of several different sections, each with a characteristic individual voice. You probably won't like all the voices, and that is part of the point of Dana's choice. The effect is to give the reader the sense that the steadily building crisis - an alien invasion - is progressively drawing all kinds of people into its vortex. Whether you like them or not, these are the people who you are thrown into close contact with.
Of course, the different voices and stories begin to overlap and blend as the action progresses. Strands of the story which initially appear quite separate are tied together. Dana seems to have a great enthusiasm for acronyms, especially military ones, but there is a helpful glossary if you get lost.
I liked Dana's depiction of a group of worlds which still retain a lot of the original Earth society which settled them. The several planets whose lifestyle is drawn for us differ in many ways, and old alliances and rivalries have a way of resurfacing. It is, I think, all too likely that our current national differences will not disappear overnight just because we discover feasible interstellar travel.
Outward Frontier is only the first book, and it is clear that the saga will continue at some stage. However, it comes to a satisfying conclusion, at which the reader is left with the sense that although the immediate crisis has been weathered, there is a great deal more conflict, intrigue, and discovery to take place.