I had a spec 3 in my 04 Cobra and loved it. So people have had problems with shuddering type issues when leaving from a stop. I usually left a little more aggressive and had no issues, but they do have a tendency to shudder with a slow slipping type of application (ie. leaving a light like Ms Daisy). Mine held up to 600+ at the rear wheel with no problems at all for well over a year of good abuse.