I would say it is recommended. I run it on my NSRT-4. It can do many things. It can richen your air fuel mix, lower your air inlet temps, etc. If you go to srtforums.com there is lots of good info on it.
In normal conditions its not going to do anything. In a modern turbo car [if the car has adaptive timing learn] the car can gain horsepower by thinking it has better octane in the car and raising timing. This is usually very marginal.
The big gains come from tuning the car to run on it. Raising boost and raising timing will show some pretty decent gains if tuned correctly.
It can also be used as a small octane booster for 91 octane guys if your not wanting to rely heavily on it