> Nietzsche's moral cynicism is universal and the MS divide is meant to be descriptive, not prescriptive or constructive.

Could you elaborate? Nietzsche's usage of slave morality seems pejorative to me, and I wouldn't characterise Nietzsche's stance as an universal moral cynicism; his method does not aim at an universal conclusion.

Funny enough, this illustrates well why it is difficult to find good reads on Nietzsche, it is not easy to summarise his positions briefly and without equivocation.