Kings of Cool is the prequel to Savages, and very much of a piece with it. The same punchy style. The same lack of depth. It's a bit worse for being a prequel -- I rarely like prequels, because a whole lot of the plot revolves around getting the characters into place for the next book, which we've already read. The biggest pluses for this book are that the style is enough fun to get over the other hurdles, and the novel is short enough that its annoyances don't really build up.
But I'll be happy to read the next Neal Carey book, which should have a bit of substance.