After the cliff-hanger ending to Starfish, I was really excited about starting Maelstrom. That excitement steadily drained away over the course of this dreary book, until by the end I had precisely zero interest in the series.
Why is that? One factor is that while Starfish had a developing plot line and unraveling mysteries, in Maelstrom things just fall apart. The entire book is about people trying and failing to contain viruses, mostly because the world's author has decided he doesn't like people and wants their defenders to have really bad luck. A second factor is that in this book Watts stops writing about what he knows (marine biology), and starts writing about things he doesn't know (computers and people).
The many parts of the book that talk about future computers and future internet and future computer viruses are just painful. Watts is intent on applying his biological models to absolutely everything, and ends up with these absurd computer viruses and computing paradigms. In his world virtually every computer is running Windows 95 and has been rooted, and viruses are continually playing elaborate games of Core Wars in order to propagate themselves, and none of the ruthless, all controlling mega-corps have just said f'it and made their networks into fully trusted walled gardens.
The sections on personal motivation are no better. Every main character turns out to be some sort of anarchic nihilist, who would much rather watch the world burn than, say, continue to enjoy their luxurious upper-class existence (spoiler!). There is one exception to this, but apparently she is the villain? It is a bit like reading a Warhammer 40K book, if it was set entirely amongst Nurgle and Tzeentch cultists, and if the gleeful absurdity of 40K was drained out and replaced with a sort of adolescent anger and self importance. Watt's caustic view on things can be enjoyable when diluted with other plot lines, but in Maelstrom he just kind of wallows in it for 350 pages.
Overall the experience of reading the two books was a bit like reading Watt's blog. At first there are some good entries, but then you come across ones like where he goes to a con and makes an ass out of himself (http://www.rifters.com/crawl/?p=1488). You then realize that in addition to his admirable qualities, Watts is also kind of an angry and self-righteous drunk.