You are going to get a lot of varied response on that one but I'll throw in my two cents. I have always been die hard Flowmaster and I still think they make a great sounding product. But I recently decided to replace the Super 44 on my 4.7 (right before I ended up trading it oddly enough) with something a little quieter. I went with an 18" Magnaflow and wow!!! Not only did it sound absolutely awesome but I truly felt a little more bottom end and saw a small MPG increase. The truck I traded for has a Flowmaster on it and it sounds good but when it needs replacing or when I find some extra cash it's getting a Magnaflow.