I just installed a brute on my truck and i love it. It seems to have more throttle response and power through the whole RPM range, it don't feel like its gasping for more air. Don't know about the gas mileage yet find out in a while, but how good can you expect from a 6.0L 2500HD anyways.

I wouldn't expect any increase in MPG with just an intake. The engine needs to exhaust the air easier if its taking it in easier in order to see an increase. At least, thats been my findings in the past.