I think e reprise is a good "utility" tool now. It's a skill you can use if you have to move around due to mechanics, since it has a good mana to potency ratio and the lost GCD isn't a factor in this scenario. It's also a good way to dump some mana if you are close to cap or close to/over 50 with manafication ready but due to mechanics you can't rush in for the melee combo at the moment (though i'm not sure if you'd be better off just normally casting in this scenario, i didn't take a look at the numbers)