I haven't personally, but there is a guy over on s197forum that had the kit installed for a while on a 2011/12 GT 5.0 ... ended up taking the kit off as he couldn't get it to run correctly and make good power due to design issues. Piping is too small and overall the kit isn't designed to produce safe pressure levels (between the engine and Turbo). He lost serious money on the deal and ended up trading his car in after pulling the kit off. I bought some other parts from him which he had taken off the car. Overall, it turned into a disaster for him. I did talk to him a little via email and his story sounded true. There is another thread on the same forum which has car that started with a Hellion kit, only to have it taken off and a custom Turbo kit fabricated instead.
Fixing the kit requires requires extensive modifications, new BOV or WG (forget which), piping modifications, etc. Not worth it when there are other options coming to market.