I have a 2011 GMC HD Z71 with the 6.6. I've been asked by hypertech if I'd be willing to participate in some beta testing for their yet to be released 2011 model year tuner. I've not read much bad about them, but was curious if anyone had experience with their equipment on later model trucks. There's lots out there about performance on 2004, 2005 models, etc. But what about 2009 & 2010 models? Anyone got any other general advice about them?