ASR Emitter Upgrade

I have a 2008 ASR Emitter Exclusive Blue. I see that there is now an upgrade kit for 360 dollars that can be obtained. Would like to know from other ASR Emitter owners if it is a worthwhile upgrade and how difficult is it to do, mainly how many resistors have to be removed and replaced. And also the most important part is how does is effect the sound. Thanks for your responses.