[John Y]

From personal experience, I would urge you to go with GIAC out of those three.

As with all normally-aspirated engines, gains from chipping will never come close to the benefit a turbocharged car will see - it will be a modest gain, especially on an engine where the manufacturer has gone further down the road towards maximizing stock power than most mass-market manufacturers will. Lots of people seem to forget that, or haven't had previous chipped experience with either a turbo or normally-aspirated engine, which is why they are disappointed.

Whether such modest improvements are worth the price is up to you. The fact is that there is not alot of additional power to be squeezed out of these engines unless you are going to add a turbo- or supercharger.