No more Cab noise
I had my resonator taken off due to a large dent and hole in it and couldn't stand the hum I would hear in the cab. I didn't realize how important the resonator was. I had this welded on and the cab is back to normal without the noise. I have also noticed a slight increase in fuel mileage / power. If someone says the resonator is not important and you won't notice with it taken off is wrong.
Quality engineered part
It's pretty simple. Rattle trap exhaust is now smooth reving, with zero loss of power after updated dyno. Only issue would be weight, pretty heavy part to add in. One of the ideas behind this Hummer H3 was to reduce weight and all lite weight exhaust just got killed back to stock weight with this installed.