I've had mine for quite a while and also had the initial "wont start" problem. Turned out it was one of the plugs not totally seated.
Took a couple of days for the LTFT's to settle down then ran really good.
After a while and all the haters of this product slaming it I removed it,,, my power went down noticably, took a lot longer to spool up. Re-installed it again after just 4 days running without it!!
I guess all the haters never really installed one on their own car!
I have no idea how much power it gave me but I'm not complaining at all. Could it be better? Shure!! If I got a custom tune! For something that is plug-n-play though, not bad!