Without the rear cans, it is louder than stock, certainly. Enough that I can remote start my car from 150 ft away in an empty parking garage at work and hear it, then listen to it idle. With the rear cans in place, I could barely hear it start and no way could I hear the idle. It has a nice tone to it as long as you stay out of AFM mode. Not that AFM mode sounds horrible, it just doesn't sound pleasing to my ears.
When I say it isn't loud enough, in comparison to my V6 and the Solo exhaust, I mean that my wife can no longer hear me (from inside the house) take off from the stop light that is 1/4 mile away.
I can't imagine any axle back kit being any louder than a straight pipe, unless you remove some of the restrictions upstream (resonator, cats).