Most, not all but most, tuners are piggyback models that usually just add fuel. Yes they can make lean conditions disappear but they are limited by reading the signal sent to the injector and modifying it a little. And if you over supply gas it just gets tossed out the exhaust pipe. After the spark fires there is only so much time for X amount of air and fuel to burn before the exhaust port is opened.
That is my view. Others have differing views. My suggestion is to research things on the web with credible sources.
Ivan's Flash is different in that he modifies the actual ECU code. His website lists what he does and he also will talk to you live if you still have additional questions.
Also, if you have a willing member close by you could go for a ride and swap ECU's half way etc. The Flash is the same for all bikes. You'll see the difference first hand that way!! Trust me, it'll be hard giving back that ECU and you'll be mailing yours to Ivan ASAP. Fair cost would be a tank of gas and lunch!!