I had mine done on my quad,,,I now for a fact that it adds power. I didn't get my quad dynoed before and after, however there are others that did. And they picked up 1 to 3 HP. For the amount that you spend on other items to gain that much power, boring your carb makes sense. What sucks is re-jetting, it takes time.
I know we are talking about a RHino here but it is the same motor that is in Raptors. So it will help.