Pinnacle's shampoo is good stuff. It's like sending your car to a salon for some pampering. Very luxurious, good at cleaning, smells great, most bubbles I've come across. Overall, better than GC except for one thing: it seems to be harsh on waxes. The paint becomes squeeky as if all wax has been removed.
I've stayed with NXT Wash because it is almost as sudsy, cleans just as good and is kind to waxes. It is also much cheaper. While NXT smells great, nothing compares to Pinnacle's fragrance.