You FOOL
The eternal reward can be incredibly useful, if you pair it with the stock disguise watch and a revolver that boosts cloak it can be ruthlessly efficient. The kill is silent (the knife sound is still heard but it silences the scream) and it instantly switches your disguise to the person you just killed and hides their body instantly, meaning another member of their team only has to turn their back for one second and they won't see a thing. It doesn't have the advantage of the dead ringer, but usually you won't need to cloak because of how quickly you can replace a player. The only real downside is its very punishing if you miss a stab or the enemy sees through your disguise. The stock invis watch and cloak boosting revolver makes up for the cloak drain rate that the eternal reward has, so cloaking is still a decent escape option.