How GREAT was Scizor ACTUALLY? – History of Scizor in Competitive Pokemon (Gens 2-7)
Scyther is a fast sweeper that is fragile, but makes better use of Aerial Ace+Technician because of STAB. Scizor is more durable but slower, but Life Orb+Technician+Swords Dance+Quick Attack can hurt a lot of faster stuff, which as a rule tend to be less stable.