I can attest to the quiet power of the UltraFlo mufflers... I had a 2 1/2" cat back system as one of the first mods to my car and really like the sound they produce, unlike Flowmasters. I work at a muffler shop (family owned/operated) and have installed few hundred Flowmasters myself... not too many people around here run the UltraFlo muffler, so someone always commented on the sound of my 'stang compared to others when it was bolt-on car. I later put turn downs on and it still was relatively quiet at idle (for a car with turndowns)... but when you put your foot to the floor it sounds wicked!
I have 2 1/2 Magnaflow mufflers w/ turn downs now... the stainless versions are actually a step above the Ultraflo muffler in that they are a fully welded stainless muff compared the the stainless UltraFlo's rolled seams... They sound the same to me... The welded UltraFlo's are only available in aluminized, btw... and are quite a bit bigger (thicker, wider)
The Magnaflow cat back for the LX's (I've installed three systems so far) come with 3" tailpipes and that makes it a louder system overall, with a slighty more noticeable idle than the Dynomax cat back.... so if your going full system, I would actually recommend the UltraFlo system (for stealthy reasons, otherwise get Magnaflow)
.02 cents on the matter, or more
