I got mine this past summer. I love it. It is full stainless steel too. Will last alot longer than others. Sound is not any louder at idle. It kinda burbles around town, and at WOT it is very loud and intrusive. Very brash metallic and deep bass sounding at wot.
For pure sound though.. Tanabe RM. I was sitting behind gritsak at idle, and his car was drowning mine out! Very deep bass sound. Very nice.
But for total package, IMO the gt spec is the best.