I suspect that the book's main audience will be Zelazny fans like myself, hoping for 1) hitherto unpublished literary gems unearthed by the editors' diligence, 2) some insights into those aspects of Zelazny's life and background which made it possible for him to produce his work, and 3) a convenient volume including our favourite pieces. NESFA have delivered on all three. A lot of the uncollected pieces here are rather minor, but there were a couple which jumped out at me as memorable ("Final Dining", "Circe Has Her Problems"). There is a decent amount of explanatory biographical material by co-editor Kovacs, Carl Yoke and a preface by Robert Silverberg. And this first volume includes "A Rose for Ecclesiastes", "The Doors Of His Face, The Lamps Of His Mouth" and "He Who Shapes", Zelazny's best early stories, which is a powerful mixture.
Satisfying those three requirements would just about justify the hefty $29 price of this hardback. But there are several other positive points about it. First, a lot of Zelazny's early poetry is collected here, interspersed through the stories, certainly at a pace where I could appreciate it. Second, and probably deserving to be mentioned before this, there is a brilliant Michael Whelan cover which will apparently span the jackets of all six volumes. Third, each story and poem has, if available, a short epilogue from Zelazny himself explaining his own feelings about it, and also a glossary of literary references (most of which are accurate, though I wouldn't be surprised if the Miller whose writing has emetic effects is Henry rather than Arthur).
So, apart from its obvious appeal to existing fans, I think volume one at least is well-designed as a gateway book to encourage new sf readers to read more Zelazny and just to read more widely. "A Rose for Ecclesiastes" is a really powerful story to begin with - consciously old-fashioned but doing something new as well. "He Who Shapes", drawing as it does on Zelazny's own experience of car accidents and bereavement, is a good ending point for this first selection. The commentary keeps us going through the less memorable stories in the middle. I am looking forward to reading volume two, and to buying the rest as they come out.