Well now you're in subjective territory, regarding whether anyone will "notice" or "improve". There's no doubt that tuning will produce more power and optimized throttle response curves that a stock EPA-compliant map simply can't produce. Whether it's "worth it" is totally up to the individual. I know I'd never put a performance exhaust on a bike and not tune for it, regardless of whether it was the DP with Up-Map or the Evo line exhaust which I'd pair with a Rapid Bike unit. Every tuned bike I've ever had has ran cooler and had better throttle response, regardless of how much more additional power they made.
Remember the days when we put an expansion chamber on our two strokes or 4 into 1's on our Kwaka 9's. No one care about any ECU tune because there was none. We perhaps got some performance gains and it was all fun. They always sounded better.
And of course it went better. It must have we just paid all that money.
Roll forward a few years. When I got my full Akra after a 4 month wait. $3400 USD. Too much hell yeah, way overpriced, perhaps. But I wanted it and a fool and his money are soon parted.
So I fitted it and as I posted in detail. Yes it sounded better. It was louder as I checked with a sound meter before and after. It is way way lighter as I weighed all parts before and after.
But did a feel a power or performance gain. No, Zero, Nada, Nil. Even at that point I was still happy as I thought still worthwhile.
Later after a custom dyno tune by Wayne Tuneboy and fitting a SBK MWR filter at the same time I picked up nearly 8 Hp. Did I notice that ? Hell yeah but that was more to do with flattening the torque curve between about 4500rpm and 6000 rpm.
I have posted all this before but thought would chime in with some thoughts. Would I do it all again. Yes. I love that exhaust but part of the process for me is fitting the parts myself, admiring the Ti, weighing parts comparing bits from OEM etc.
You make your choice, you pay your money or not. Simple. Hint for the new players. Do your own research. And buy for yourself and not what you think will impress on the forum. BTW although I have responded to Jarel, I agree with what he says it is not a counter post.