I've used PTC,Lupo, and Turbo Action in years past. All have worked pretty well. Lupo wanted an arm and leg for refresh. The current car has used ATI and Ultimate. I chased ET with Lenny this summer having no dyno sheet. He was pretty close right off the bat. We tried a couple different ideas. At one time the ATI was the quickest, but not anymore. That being said best to worst wasn't much over .10-15 in ET
Doug