Tanabe RM = crazy loud. I would stay away from Tanabe altogether to be honest.

What youre describing is exactly what you would get with an Apex'i WS. Pretty quiet, not annoying while cruising, deep, not rattly or raspy at ALL, and sounds great @ WOT. Get the WS.

If the WS isnt loud enough for you, the Evo is the next step up. A bit more raspy, and louder all around.