Love it. It is still loud outside the truck...but most of that is engine noise. However, you can now lean on the fenders or tailgate and actually hold a conversation with someone. I think if you want really quiet....put a actual "muffler" after it....but I don't have room. Mine comes out and turns up too quick as I'm crossing over the frame rail under the truck and not in the bed to the front corner. But I don't think any more muffling would do any good because the valve train and engine noise on this 2002 is horrendous. I think a better investment would be $2000 worth of dyna mat.
This is a resonator...it does quiet it down...but the resonance is G.O.N.E. at all RPM's. If you want completely quiet, buy a muffler. As for this dude..it works.
It depends on what you weld in the center. If you buy the flighting, it won't have anything in there. Insert your own tube or pipe. If you take a grain auger apart, you could cut the welds and insert a hollow tube.