Persistence would be excellent for Monte Carlo, but I've never had any problems with mine. It's great for a Warlock, especially with Claws of Ahamkara. As a sunsinger you can have a shield ready much more often (and so win double melee fights in the crucible more often), and as a voidwalker it lets you trigger energy drain more often, which gives you more grenades, and your grenades give you more grenades, and supers, and then your super gives you more grenades. It's wonderful. You can even lead with your buffed melee, finish with Monte Carlo, and have a chance to get your melee back instantly, and repeat.