I do not have to tell you how awesome the CBR 1000 RR is. If you are reading this the opportunities are you have one and you know the power it offers. One other thing you will also know is that the stock exhaust has to go. Of course that is the first thing that has to be upgraded right? So what exhaust do you get? There are a lot of options available for the CBR 1000 RR but not all are made alike. Some scream like a banshee and others growl. Hyperflo is one that gives a good solid growl. I have heard others that just seem to sound, well, cheap. You can listen to most if not all options on YouTube and get a good idea of the sound that each exhaust option makes.
For most, changing the exhaust is not about performance so much as most of them do not change much. You will get a little increase in horse power sometimes with this change and I guess adding 1 or 2 HP can make a difference. The aftermarket exhausts add a lot as far as identifying taste however. Each aftermarket exhaust has its own look and this reflects your taste as a rider. As far as the sound goes I guess that is a matter of taste as well. Some would say "If you do not mind having an exhaust that screams like a girl then Two Brothers might be a good choice for you." They have that banshee screaming sound. Personally I like more of a deep mean sound.
Another thing that is helpful with the aftermarket exhaust is the downsizing of weight. No, I do not mean you as a rider but rather the exhaust weight added to the bike. Some aftermarket exhausts will take off a few pounds from stock so that can also help. If you combine 1-2 HP gains and 1-5 lb lower weight then you can see the potential for increased performance for the bike. When it comes right down to it however, it is not just about the bike. Let's be honest and admit that the rider makes all the difference. Your ability and experience is still going to be the largest variable. If you are a good rider however, then even a small change in weight or horsepower can make a big difference in your overall performance.
What is really important?
When it comes down to it there are many things you might think about that are important with an exhaust. Of course you have the mechanics of it and you need something that will allow exhaust to escape the engine. If it works efficiently enough then it will improve the overall performance of the engine. Releasing this exhaust in an efficient manner from the system can help the bike perform better and with more power so this is definitely something to keep in mind with an aftermarket exhaust.