This is very hard to judge. Videos suck to base on it because of the equipment used and trying to make it a digital sound. Personally, ask in your local section of forum who has what, and see if they will let you listen to it in person. After a few tries at this to various car shows, I found a setup I liked, and waited until I found a good deal on it. At first I had SLP lm I setup. That was fine until I saw the deal I was waiting for. Now I have TSP headers with magnaflow x-pipe, mids and cat back. It's nice, and surprisingly not crazy obnoxious for being 3" from headers back.
The car is gone, I will be back... when's the 6th gen ZL1?