I purchased and I can tell you that yes, it improves the power on the lower speed to get fast easy.
However, the bigger improvement was on the noise. And was big enough that I decide to remove it, since it was anoying. Also, the engine didn't feel so stable as with the original set...
I think that I had it install for a day or two.
So, If you don't want to spend that money, mine is available for 160$.
Carlos