I can't speak for the Stinger, but I had the full Banks, including Transcommand installed on my 310hp V-10, and I was very disappointed. The only thing I can say that was noticeable was the shift pattern was much better. As far as power is concerned - nothing I could notice. I now have a 362HP V-10 that weighs nearly 6K more, and it performs as well as the other one with the Banks. I would never do it again. What I saw was not close to worth the money.
Now, you are going to hear many people who are completely satisfied with Banks.
The issue might be the application. I here people with 460 Fords talk about a big change. It also sounds like Diesel applications under the right conditions make a difference. I think Ford has managed to get about all there is out of the 362 and the newer five speed tranny.
Good luck with whatever you decide to do, and travel safe.