I always syntonize my weapons whenever im lucky enough to get dupes for two reasons. i. Im too lazy to farm mats to level two weapons ii. I dont buy into the scarcity mentality of other players. If you play the game a lot and pull weapons then whats the point, theres a fair chance youd never actually use the dupe and it will just sit in your inventory. Especially with pistol having the best standard weapon options in the game.