Problem with monkeying around with pipes is you screw up the air flow dynamics thru the whole motor, & can lose power and gas mileage, foul your plugs and burn your valves.
Sure... if your stupid enough to not run a tuning device on your bike...
That's just idiotic. Even on my stock R6, I run a tuner because its a nice and cheap $180 usb device that evens out your power, specially in the low band once you get your mapping down right. I'm lucky since I know a few owners in my area that have a dyno so I can make sure I'm running the right fuel/air ratios across the board.
The downside is that with either of my r6, the power band is very aggressive since it has 5 valves per cylinder; the top end acts like a turbo and if I'm not careful (or if I was and just wanted to...) I can fish tale the rear right around 10k if I just give it gas in corners. Sometimes I can hold the drift, but most of the time, I just back it off so I can get grip again; not risk coming out of the turn with a tank slapper. But again, on the track, I'm never below 9k rpm's or the very start of the top end powerband.
A properly tuned sports bike is what you want. Although I do want to get a better tunning package that features more sensors and customization (specially the ones with quick shifting packages), but I can't justify spending $900+ for such a system when I can throw that money into better suspension, but then again, my riding skill isn't good enough to warrant such a suspension. And if I had that kind of money, I'd throw it away on some magnesium wheels.
Honestly, I just I'd use that 900 to afford more track days cause they both are just sitting in my garage taking up space.
And honestly, putting a jet kit on any carb bike is a worthless adventure. Did it on my F2 and took it off immediately. This is why GOD made FI (aka Fuel Injection)... lol screw all of that old crap. Give me a usb tuner and a laptop and I'm all good.