Storage [Q] Best ROM in terms of performance?

Could anyone give me suggestions and advice as to what the best ROM would be for our devices, in terms of speed.. just like MERE (Most Epic Rom Ever). As I'm planning to downgrade to either 4.2 or 4.3, as I am pretty much disappointed with Kitkat.. for now. Thanks! Im running on Android Kitkat 4.4.2 Pre-rooted