What's most interesting about this book is that it's a posthumous collaboration. Bester had completed only half the book upon his death in 1987. Zelazny was offered the opportunity to finish the book of one of Sci-Fi's early greats, and he accepted the challenge. He completed all but the final touches before his own death in 1995. Three years later it was published. The result is a novel which is full-bodied and dynamic, written as though by a single mind. There are only a few sentences or turns of phrase I could label as pure Zelazny.
Another excellent book by Bester is The Stars My Destination, published as Tiger! Tiger! in the UK in 1956, and then republished in the US in 1957 under its original title (the one it bears now) from a printing in Galaxy Magazine (1956). The Vintage printing includes a foreward by Niel Gaiman, who dexscribes the book and praises its author much better than I can.