the micron has a deeper, louder tone and also gives more hp & torque
BRAND.........................WEIGHT(lbs)........DB...........HP.............TORQUE
Micron (high mount)........10.5.................104..........109.............45.5
Yoshimura........................5.7...................99...........107.3...........44.7
Stock...............................11?..................88?..........106.4...........44.4