I've been running the monster tune since early May and since then I can honestly say the car has never run better. I daily the car so its seen alot of miles and mountain runs with no issues. This is one of the safest stock turbo tunes you can get for the focus st / fiesta st. I promise you won't be disappointed if you switch from a competitor tune. I even think he gives you a little discount if your switching from a competitor. Pretty good and responsive customer service, you won't be waiting a week or two for you tune. Check it out!!