I play seven string guitars, but with a Drop A tuning.
I play metal, and started with the standard 7 string tuning, and it sounded great, but I really love the “grind” of Cannibal Corpse. There is a certain tonality that Drop A provides with the right kind of gain that is incredibly satisfying.
WhatI love about this tuning is that I am not playing death metal (instead thrash mixed with classic rock), and this means I can play the classic rock elements in standard tuning (by using the E - E strings. Then, when I want to add some grunt, I drop down to the Drop A. I love the combo.
I tested this while playing a transposed version of Tornado Of Souls. It sounded killer!
I will never go back.