The 2.5" and flo master isnt that loud realy, unless youre above 3K rpms.
I realy dont notice the GT droning down the highway.
but the SE has headers and is a little more droning sometimes when trying to talk, on the phone.
Both just have stock radios , and it drownds it out pretty well.
After a few 1000 miles the tone does kinda mellow.