While the RCT lowers sound, what's better is that it won't eat up your bike's power either. In Fact the RCT chamber design refines and enhances exhaust pressure to give your bike gains throughout the rpm range.
I replaced my stock pipe with the FMF and all it did was make it sound wimpy and took away lots of back pressure that the stock pipe supplied. I entered a race without testing and was blowing through corners and was annoyed with the tone that the pipe was giving my motor. It looks bad ass but i will be selling a brand new pipe with one ride if your interested let me know