Spark provides a capable, free‑first experience with AI‑driven inbox organization, making it a solid choice for most users (TechRadar). Superhuman’s ultra‑fast interface and shortcut‑heavy workflow deliver superior speed, but its $30 / mo price and Gmail‑only focus limit its appeal (CNET, The Verge). For budget‑conscious users Spark wins, while power‑users who need speed may prefer Superhuman.