They are a great compromise between the stock exhaust which many people think is much too quiet and something like the Borla Attack which some people think is too loud. I installed the GT500s and really like the muscle sound during acceleration but appreciate the relative quiet and lack of drone at highway speeds.
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.