I have the short body installed on my '02 Silverado.
For the most part I like the sound of it a lot. However it is a lot more "throaty" than I was hoping for. It sounds like it is actually holding back a lot of the exhaust, however, the design is a lot more efficient than the flowmaster.
Also the turning point for me when purchasing this product was the fact that it has a lifetime warranty. Very good subject in my perspective.