Just a Benson with hydro? :) I think that is a significant difference, tho you forgot to mention 1 turret trade off.
I will never buy Leningrad for one obvious reason. It requires different build that my Khaba and my Kiev use. Dont get me wrong, I love russkie DDs, and Leningrad is one of them.
Its fast, the guns are great (the they turn pretty slow) and the ship handles like a brick :) But If I cant use it as my RU DD trainer because it requires different build, I see no point of getting her.
Specially since at T7 there are some top notch premiums available.