I've been using the PPE Xcelerator on tune "2"for 6 months now and it produces Xcellent power. I get about 1 mpg better economy, i.e. 17.5 (winter) and 21 (summer). When first programming it, the shifts were not good, but have improved significantly since the truck re-learned the new power settings. Also, the latest program revison for the tuner addresses this issue I am told and plan on sending it in for that update. Thus far I am 100% satisfied with the power output... Here's a story to support this...
A couple days ago a VW jetta was behind me and decided he didn't want to be behind me anymore, I guess he didn't like big trucks. He proceeds to pull up next to me at the next stop light. The light turns green and I'm xcelerating normaly, he apparently didn't like being next to me either. I hear his engine rev and he starts to pull away. I thought hmmm - NO, so I rolled on the throttle to about 3/4, heard the turbo spool, (we're running about 40mph at this point), and the truck went sideways, you know, spinning the tires. I let off a bit and the truck leaped ahead of him and I beat him by about 4 or 5 truck lengths up to 110mph. Needless to say I'm sold on the PPE.
Oh yeah, I have never thrown an engine code either.
Andy