Having recently finished _On Writing_, I completely agree with Mr. Brading's earlier review: this collection is unnecessary, especially considering that the best of these essays can be found in _Selected Non-Fictions_ for only a few dollars more.
This anthology promises to be "a master class in the art of writing," but that is a bit misleading; this is simply a collection of essays about poetry and fiction by an amazingly well-read and highly creative writer. Using the book's definition, the majority of Borges's non-fiction writing could equally be categorized as a master class in writing. If that's the case, _Selected Non-Fictions_ is simply a better class -- more comprehensive and cost effective.
Aside from a few points here and there (mostly related to the detective genre), nothing in _On Writing_ particularly stands out as offering insight into how one can refine his or her own craft. Try as it might, this collection is not a creative writing handbook; it ultimately reveals much more about Borges and the kind of literature he enjoyed than it does about the writing process itself. If there is an overarching lesson about writing presented here, it is to read as much as one possibly can. This is valuable advice, but hardly earth shattering.
That's not to say that these essays aren't interesting; they are. As with Mr. Brading, my complaints are against this particular anthology, not against Borges's writing. Borges's non-fiction is at times as enjoyable as his poetry or short fiction, revealing an author with an awe-inspiring, wide-ranging love of literature and philosophy. (The importance he places on broad reading habits and reading for pleasure is especially welcome for those of us in higher education who find ourselves pressured by demands for narrow, research-based specialization.) Again, readers of _On Writing_ will get a taste of this but have a much richer experience with _Selected Non-Fictions_.
However, those curious in specifically learning more about Borges and his approach to writing and reading literature -- for him, the two concepts went hand-in-hand -- might be better served by locating some of his interviews or lectures, such as those collected in _Borges the Poet_, ed. Carlos Cortinez (ISBN: 093862637X), and _Seven Conversations with Jorge Luis Borges_ by Fernando Sorrentino (ISBN: 1589880609). To anyone who has access to a university library, I would also recommend "Weary of Labyrinths," a particularly good Borges interview by Cesar Fernandez Moreno that appeared in English translation in the magazine _Encounter_, volume 32.4 (1969).