But I have never used anything else, so I couldn't give you any real comparison. But I will tell you that I have no problems boosting 1.1 to 1.2 bar of boost. I have driving a stock TT with pre-cats, and I will say that boosting my Z at that same level, you can tell a difference. The only thing is, J-spec downpipes are really not a cheap alternative. Unless you happen to have an NA exhaust laying around. The Jspec DP's ONLY bolt up to NA midpipes/cat-sections.