Vibrant Performance resonators to reduce rasp?

So I currently have a muffler delete and a h-pipe resonator delete and the volume and tone is great in the low rpm range but as soon as I get on it hard the rasp is pretty bad. I would have put the suitcase back on if it wasn't for the difference in power it made, the car seriously feels faster with no mufflers or resonator. The performance resonator by Vibrant http://www.summitracing.com/parts/vpe-1792/overview/ claim to reduce volume and rasp without restricting flow.

Anyone have any experince with these or "performance" resonators in general?

I have the 3" version on my 5.0, love them

For those that have installed "bullet style" resonators, how much did it decrease the loudness volume?