I had one installed a month ago. I have driven around 800 miles since the installation and I really like it. I have had no problems and the gas mileage has not changed under normal driving. Mine was installed by the corvette dealer I bought the car from. It took them around 17 hrs to install. I have an automatic transmission and I am very impressed by the difference in performance.
Car is a 3LT, Z51 with Exhaust and Suspension options.