This. I actually would go a step further and say that the GT500's are very mild. Louder than stock but definitely not smack between Borla ATAK's but between stock and S Types, closer to stock.
I've only had my GT500s for a short time and apparently they get louder over time, but I do find them to still be pretty mild in the higher revs.
-2012 Grabber Blue GT 6M Premium w/ Brembos, Glass Roof, HID security pkg, Rear Camera, 401a, FRPP GT500 Axle-backs, Front Pioneer TS-D6802R speakers, JHR bracket, Bondra clutch extension.
-1986 Mazda RX-7 GX - Fast Mirage 16" Wheels, Sumo Firenza 205/60R Tires, slotted brakes + performance pads. Otherwise factory stock.
-2008 Mazda Mazda3 GT Sport - Stock, 5MT.
-2004 Volvo XC90 T5 - Comfort pkg, safety pkg.
-1995 Infiniti G20 - Sold, Pioneer head unit, lighting mods, miss it dearly.