The V10 is not at all optimally set up from the factory. Five Star specializes in V10's and arguably knows them better than anyone in the industry.
When it comes time for my tuner (got to get some other things taken care of on the truck) it will come from five star.
Give them a call and ask for Mike. He is a great guy to talk to and there have been no negative reports found on the net about his V10 tunes. If the Internet has proven anything it's that if there is any little problem with a product or service... It will be on the web.
Thanks!