I installed my friends tanabe exhaust on his 2nd gen integra. Before we put on the exhaust, we started the car with just the catalytic converter on to see what is sounded like. Then we put on the exhaust, and they sounded exactly the same. That exhaust is so damn loud. I have to cover my ears when he goes by!
I like the sound of the Greddy exhaust. Not too loud, not too soft. It's just right.
If you want to go stealth, then go with a DC Sports. That's what I have. That thing is so quiet. You can't hear my exhaust until I start to produce boost and it's still hard to hear.
good luck,
aj