This one really hit the spot!
Excepting the poorly reproduced photos (still, they're better than nothing), this is a well illustrated book (with diagrams of specimens by scientists, and nice line drawn illustrations of reconstructions of the fauna by Marianne Collins), and technical enough to be challenging without being so technical as to completely lose the layman.
Gould is also good on broader contexts, situating the whole story in amongst a biography of Walcott himself, and a portrait of the times, and drawing out how the man and the times conspired to, according to Gould, mis-read the story of the Burgess Shale quite spectacularly. I'm totally with Gould in wondering why knowledge of this episode in evolution isn't more widely discussed and known... it's so incredibly exciting and fascinating.
Gould's another of these science proselytisers that I find very inspiring. Sometimes a bit up himself perhaps (tho' it's a different brand of up himself from Dawkins, who he apparently had something of a tiff with!), but undoubtedly able to tell an interesting story very well, covering much ground and many bases with verve.
Subsequently I've discovered that things have moved on in this area, and Gould's interpretation has itself been called into question. Sadly he's now dead, and can't continue to be involved in this fascinating and ever evolving debate. But his books live on, and make great reading.