I ran the bills pipe for about a year or two. Bills was one of the first manufacturers to come out with a pipe for the zilla. I did not like it. It was marginally better than stock--but just... Was a low end grunt pipe. I had a paul turner I liked a little better than the bills than I have run a CT pipe for about 20 years. CT was by far the best of those two. I just bought a Qv2 but have not run it yet (rebuild/Restore project)