This is the second James Swallow Trek novel I've read, as well as the second Titan novel I've read. Like the other Swallow novel, the pacing is measured almost to perfection, the characters are easily distinguished and easily likeable, and there's a crazy big dumb object out there that's going to ruin everything unless our heroes put a stop to it. Like the other Titan novel, this one feels much like classic Star Trek in the sense that the whole plot more or less revolves around a big moral question.
So, Synthesis has a lot going for it, and I think it will satisfy most Trek readers. There were a couple of things about it that I thought were particularly outstanding. First: I felt like the Titan crewmembers that this story focused on were easy to get to know and care about. That's not so easy when the majority of these characters are ones that were not ones known from the TV shows and movies. These were new characters, and establishing equity between them and the ones already established on TV (like Tuvok, Troi, and Riker) must be one of the special challenges of writing media tie-in fiction. Swallow strikes a comfortable balance and maintains it throughout. The other thing I really *really* liked was the "Minuet" character. She's featured on the cover of the novel, and she appears in the holodeck in chapter 1, so that part is not much of a spoiler... I can't say much more, though, without making it spoiler. Suffice it to say that she becomes much, much more than the Minuet we encountered in season 1 of Star Trek: The Next Generation. And she becomes incredibly interesting. Not only that, but Swallow deftly weaves her story in with that of Riker/Troi and Choblik (the half-cybernetic engineer from an uplifted species). It's too bad what happened to her at the end -- I can only say I'm disappointed, given the great potential that her existence gives to the future of the Titan series. This last point, I feel, is grave enough that I can subtract a star from the rating, because "Minuet" could have offered so many interesting directions for Titan to take in the future... but the conclusion of this story prevents that.
Despite what I thought about the conclusion of the "Minuet" storyline, Synthesis is a great read for any Trek fan, especially one who's read a Titan book before (or even just the Destiny trilogy). The character work, all around, is outstanding.