I've tried a Magnaflow, Flowmaster 50 and a Dynomax Super Turbo on my 3.4 4Runner. I can tell you that the Magnaflow is the loudest, then the Flowmaster 50 and the Dynomax is by far the quitest. As far as performance, I would say the Dynomax performed a little better, it does seem to have more torque than the Flowmaster. I have the Dynomax Super Turbo on my 2000 4Runner and like the sound and performance. They all sounded the same but the Dynomax sound level is between stock and the Magnaflow. I ended up installing a Monza restonated exhaust tip to quiet it even more. It now is just slightly louder than stock, it has a nice mellow growl.

Randy