I have had one of these bike since the day they came out and have put probably over 10 grand in BS on mine until I found everything that worked best together, getting the ECM flashed and tuned for your particular set-up made the BIGGEST impact and also got rid of all the bike's quirks and weird ****. A tuner is no longer needed, nor is the O2 sensor. His name is Ivan, 3 day turn around. There are many forums out there with all this information but you can find most of it at Ivansperformanceproducts.com.
Not trying to sway you this way and that, PC5 is a great product, just do some research before you spend all that money, wish I had! 🙂