I had Turner test pipes installed earlier this week and I couldn't be happier.
I have a an Agency Power axle back and factory X pipe. The AP added some needed rumble, but it did drone slightly on the highway. Not unbearable, but it was noticeable.
When I ordered the test pipes my biggest fear was increased drone but I'm happy to report that the drone is essentially gone! On the highway there is an increase in exhaust volume over stock, but it is probably quieter than just the axle back. Plus, it just sounds better. Now it's not drone, it's a mild muscle/exotic car rumble....until you get on it, then it screams way louder than the AP exhaust alone, haha. It's sort of like sound "on demand".
Anyway, I know there's a lot of info on TTP's but I thought I'd share my experience for those considering this.
Next is a BPMsport tune tonight. Anxious to feel the difference.