Positive nihilism and God Nietzsche turns his own personal (neurotic) experiences into philosophical theories. So, we read some pathetic pages where Nietzsche expresses his misogeny with ridiculous arguments, only to discover that all of that was a reaction to his failure in the love field with Lou-Salomé - the same woman who appears in the famous photo as a driver of a buggy that has Nietzsche like the horse that pulls her. In other words, the previously easily dominated Nietzsche tries to pose as superior after being dumped.
Not to mention his whole attempt to create a "superior morality" based on strength, when this is just a mask to hide his own personal emotional weakness (which we know today from the access we have to his letters). In other words, Nietzsche's books are a mere self-help made for himself.
I mean, as a theory, that sucks. As a testament to a subject with talents for psychology living in a time of madness, his books have some value. If they were written with the essence of the Confessions, losing their neurotic character, in fact the books would be much better. In that spirit, Ecce Homo would have less megalomaniacal titles.
What he writes about resentment would have a much greater validity if it had the confessional component, as he hides, it becomes a comedy. Nietzsche's work is tragicomic.