Ray,
I first installed the Aero Muffler and did notice that the turbo spooled up quicker. The MH seemed to have more low end torque. I than installed the MP-8 tuner and this really woke up my CAT. I then installed an AFE dry type filter and did not notice a difference, other than being able to remove and clean with soap and water.
I agree the Aero 5" Muffler is louder than stock. I ordered a 5" resonator that I am going to put on in front of the Aero to see if it will calm it down a little without any flow restrictions.
good luck;)