I don't have a dog in this hunt as I don't have a V. I do pay attention to tuners. My $.02 is this: Hennessey will give you a quality tune. Personally, after watching him on TV with, I believe, Jay Leno, I was less than enthralled with him. He "borrowed" a customer's car and basically took it for a joy ride with Jay, laying rubber all over and generally driving it hard, way hard, without the owner's permission. This was recently on tv, and they even commented that it was a borrowed car. Not acceptable.