3.25 stars. I came to like this one more than I thought I would. It began scattered and too quickly made the origin of the "mystery" obvious. I thought I'd spend the rest of the book rolling my eyes at our stalwart crew's obliviousness, but just 20 pages later, those closest to the conspiracy figured it out, too. What a relief! All the scattered bits of story eventually came together, as well.
There were, however, several issues that collectively lost a full star-and-a-half for me, including but not limited to: Worf being written as a caricature of himself and played only for laughs; Geordi being ridiculously prone to panic; the writer(s) (who knows which!) making obvious blunders, such as that a VISOR would indicate there was no human body heat in the middle of a building that had just blown up... the, uh, heat of an explosion might interfere with that determination, no?
In addition, there were multiple times when it made absolutely no sense that the crew on the Enterprise wouldn't be communicating with the away team on the planet directly to inform them of developing circumstances. The writers also made a big deal up front of how hot and dry the planet was - to the point that wishing someone "cool days" is a standard farewell - but then it was barely ever mentioned again, nor was it ever made a problem for our crew.
The members of an important species in the book were all pretty much interchangeable, while another important species wasn't explored enough. There also didn't seem to be any reasoning as to why all the Federation members on the planet chose a difficult life of trade and the struggles of capitalism rather than being, you know, Federation members who could pursue their true interests and dreams without having to worry about money. I suppose some people just love to suffer...?
All that said, the prose was easy to read, and I went through the bulk of it in one sitting. I found the relationships - between the ambassadors, between La Forge and an original character, even between Picard and Wesley Crusher - to be believably written. Data seemed to be pretty well understood, even though some details were incorrect (they often were in the early novels).
I wouldn't necessarily recommend it to anyone, but I wouldn't suggest specifically avoiding it, either.
I would suggest, however, that perhaps 4 different authors really aren't needed to write one 276-page novel.