Depends largely on the player and the circumstance. In general PvE play I want to lean towards Bad Juju for the most part with some circumstances where Red Death would be superior. On the flipside and more complex explanation PvP is definitely a mixed bag. Juju has a notably slower TTK yet grants more Ability kills where RD is just a butcher's tool. If facing /\/008s Juju wil skyrocket your killstreaks and you am become "deth". However RD can hold up better against more hardcore players (Like a Super-minded Void Walker.