Looking at reviews of other John Barnes books, it seems as though reviewers can't write three sentences without invoking Robert Heinlein's name, as in "Barnes continues in the vein of..." or "Writing in the spirit of...". Interestingly for this novel, Barnes has cast aside his +5 Mantle of Robert Heinlein and is instead channeling Greg Bear.
Just as in most of Greg Bear's books (such as "Blood Music", "Slant" and "Darwin's Radio") Barnes' tale presents us with a bevy of characters confronted with a looming crisis who are affected by it in different personal ways. Story threads featuring the President, a nervy reporter, the Astronaut, a college student and a Porn Star are thrown at the reader. ("Slant" had most of these, including the Porn Star.)
Often, these story threads intersect. Will the college student meet the Porn Star? Will the Porn Star meet the President? Are the President and the Astronaut star-crossed lovers? (Yes, Yes, and thankfully, No.)
Barnes' strength appears to be in building interesting, internally consistent and plausible worlds. The "device" for this book is XV. XV is like TV, but for your brain. Just plug in and feel what others are feeling. Apparently, this is a wonderful way to sustain a world-wide riot.
For the hard-SF crowd, the book picks up in the middle with computer-brain interfaces leading to Metaphysical Problems of the Self. But I think that this pushes the final portion of the book into metaphysical gobbledygook, making the ending a bit of an anticlimax.
The brisk pacing of the book makes it hard to put down, which makes for good beach reading. I only wish that the ending had more punch.