The Vampire's Edge does slightly more damage than the regular version, it also weighs only 1 pound compared to the 3 pound Chinese officer's sword. Due to the very low weight, fast attack speed, high critical chance, and good durability, the Vampire's Edge is among the best melee weapons in the game despite its lower base damage value compared to other unique melee weapons.
The Vampire's Edge belongs to Vance, and can be found in a 'sword cabinet' (labeled as such in game) in his room at Meresti station, an important location during the Blood Ties quest. Apart from its unique label, the sword cabinet's appearance is that of a normal wooden cabinet.
The cabinet is a 'Hard' level lock to unlock via lockpicking. Vance carries the key to the cabinet and may be pickpocketed, but he is a difficult target to pickpocket unnoticed, even with a Stealth Boy active. The key can, of course, also be looted from his corpse.
The sword is found with a condition of approximately 50%. It can be repaired using ordinary Chinese officer's swords and is also much more durable than the normal Chinese officer's sword.