Is 18/10 stainless steel really worth it over 18/0?

Yes, in most cases. 18/10 contains roughly 10% nickel, which improves rust resistance and gives flatware a brighter, longer-lasting polish. Specialist-subreddit threads on r/BuyItForLife repeatedly flag that cheaper 18/0 sets (and even some 'mystery grade' Amazon sets) develop rust spots after a handful of dishwasher cycles, while owners of 18/10 sets routinely report decades of use without corrosion. Note that even on 18/10 sets, the knife blades are often a different, harder steel that is more prone to spotting.