Now, that is the most shortsighted report I ever read. This guy never took the effort to get the systems in tune, and never analized what was going on. What he did do was voice a "feeling" of how things should have been. Be it understood those were HIS feelings, serving his readers' views.

As you can see from the dB readings which are objective, the tuned muffler is about half as loud as the "std" muffler. This is a 3dB gain without any effort, and with a lot of power gain. Had he tested the engine to higher rpm, he would have found quite different figures, as the std muffler gains power to the value equal with the tuned muffler. The std side exhaust dump bucket is an occarino, which has a tune of it's own
However, since the tuned muffler is a high pass system, the sound is not the most pleasant. Therefore, this muffler has friends and enemies.
By adding a low-pass muffler (which is what I did), the unpleasant high pitch note note is removed. The engine back pressure is increased slightly causing a slight power rise, and noise reduction is between 3 and 5 dB, all with a size package and weight much smaller than the Mac's.
This goes to show, that power does not equal noise