Moderately interesting, but it's hard to get past the fact that this is essentially a collection of book reviews, originally published in the 1960s, 90% of which are about books I've never read, let alone heard of. I did enjoy making connections between what Merril said of her review subjects and what I often think of books I read today (seems a bit like a case of the more things change...), and she sometimes touches on wider issues in the genre that continue to have relevance. That said, this book is probably primarily going to be aimed at people who were reading sci-fi back in the day and want to revisit their reading experiences, or academics who are focusing on the history of genre criticism.