If you get Vanya Robe + Vanya Hat, both HQ, then you're sitting at exactly the same main attribute as DL Cowls (+32). That allows you to get side stats via materia to really up your abilities (Det affects casting potency, Accuracy is important for Coil, Crit is always great, etc).

It depends on if that's worth it for you. It definitely is an upgrade over DL, but then when you're stockpiling Myths every week and running Coil, you might as well just wait for one of those two pieces to drop and then purchase the other with Myth, which would be even better over Vanya and DL, obviously.