I used it in my fazer 25.
There is only a little bit change in milage, and negligible chnge in performance.
But there are better cold starts , the engine is smooth even at very low rpm's.
If you are expecting that it will bost your performance and milage a lot then sorry you will get disappointed.
But if you are buying it for long term usase (as it has life of 1,00,000 km) and for better smoothness of engine then it would perfectly fulfill your needs.