This was the best of the 5 I've read. Like many New Frontier books, this one ends in a cliffhanger, but the story just prior to that point has a conclusion that you can feel is complete in itself.
Peter David is probably the most consistently entertaining ST author, but this was a challenge for him. I think dealing with two New Frontier crews is difficult. He pulls it off, but not as much fun, in my opinion, as some of the earlier New Frontier books. The two separate Captain--First Officer relationships just don't have the flame of Calhoun and Shelby. And Shelby isn't her same old self either. That can be good, as the future will tell, but so far I was slightly disappointed in that aspect.
Still, the book by David is the best I've seen of the Gateway series.