Just wanted to relay my experience in case some of you are looking for a great tuner. He mainly tunes Toyotas, but also has experiences with Corvettes and Evos.
I had some drivability issues with the Haltech E8 in my IS300. I called Darin up and made an appt (he's located in Orlando, FL). He's a very knowledgeable and professional person. Showed up promptly and took care of all drivability issues I had with the car while answering all my questions. Gave me a very fair price for the work rendered. I'd highly recommend him for any tuning services. Great guy to deal with.